diff --git a/.gitignore b/.gitignore
index cd5597e6..456bf1eb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@
 .vscode/
 .idea/
 cobertura.xml
+cargo-geiger/tests/snapshots/*.new
diff --git a/Cargo.lock b/Cargo.lock
index 52d5c964..926ced8c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -292,7 +292,7 @@ dependencies = [
  "serde_json",
  "sha1",
  "shell-escape",
- "syn 2.0.40",
+ "syn 2.0.60",
  "tar",
  "tempfile",
  "time",
@@ -365,7 +365,7 @@ dependencies = [
  "cargo-geiger-serde",
  "cargo-platform",
  "cargo-util",
- "cargo_metadata 0.18.1",
+ "cargo_metadata",
  "colored",
  "console",
  "fs_extra",
@@ -442,20 +442,6 @@ dependencies = [
  "thiserror",
 ]
 
-[[package]]
-name = "cargo_metadata"
-version = "0.18.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d886547e41f740c616ae73108f6eb70afe6d940c7bc697cb30f13daec073037"
-dependencies = [
- "camino",
- "cargo-platform",
- "semver",
- "serde",
- "serde_json",
- "thiserror",
-]
-
 [[package]]
 name = "cc"
 version = "1.0.83"
@@ -1017,7 +1003,7 @@ checksum = "53b153fd91e4b0147f4aced87be237c98248656bb01050b96bf3ee89220a8ddb"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
 ]
 
 [[package]]
@@ -1063,7 +1049,7 @@ dependencies = [
  "cargo-geiger-serde",
  "proc-macro2",
  "rstest",
- "syn 1.0.109",
+ "syn 2.0.60",
  "tempfile",
 ]
 
@@ -1475,7 +1461,7 @@ checksum = "02a5bcaf6704d9354a3071cede7e77d366a5980c7352e102e2c2f9b645b1d3ae"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
 ]
 
 [[package]]
@@ -2043,7 +2029,7 @@ version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a857d4b6450fbc2b85c03684b2beae51916a5a90e2fb5f9c2b8acc920ad29e49"
 dependencies = [
- "cargo_metadata 0.15.4",
+ "cargo_metadata",
  "cfg-expr",
  "petgraph",
  "semver",
@@ -2319,7 +2305,7 @@ checksum = "a948666b637a0f465e8564c73e89d4dde00d72d4d473cc972f390fc3dcee7d9c"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
 ]
 
 [[package]]
@@ -2559,9 +2545,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.78"
+version = "1.0.81"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2422ad645d89c99f8f3e6b88a9fdeca7fabeac836b1002371c4367c8f984aae"
+checksum = "3d1597b0c024618f09a9c3b8655b7e430397a36d23fdafec26d6965e9eec3eba"
 dependencies = [
  "unicode-ident",
 ]
@@ -2588,9 +2574,9 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.33"
+version = "1.0.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+checksum = "0fa76aaf39101c457836aec0ce2316dbdc3ab723cdda1c6bd4e6ad4208acaca7"
 dependencies = [
  "proc-macro2",
 ]
@@ -2748,7 +2734,7 @@ dependencies = [
  "regex",
  "relative-path",
  "rustc_version",
- "syn 2.0.40",
+ "syn 2.0.60",
  "unicode-ident",
 ]
 
@@ -2911,7 +2897,7 @@ checksum = "43576ca501357b9b071ac53cdc7da8ef0cbd9493d8df094cd821777ea6e894d3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
 ]
 
 [[package]]
@@ -3091,9 +3077,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.40"
+version = "2.0.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13fa70a4ee923979ffb522cacce59d34421ebdea5625e1073c4326ef9d2dd42e"
+checksum = "909518bc7b1c9b779f1bbf07f2929d35af9f0f37e47c6e9ef7f9dddc1e1821f3"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3156,7 +3142,7 @@ checksum = "266b2e40bc00e5a6c09c3584011e08b06f123c00362c92b975ba9843aaaa14b8"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
 ]
 
 [[package]]
@@ -3268,7 +3254,7 @@ checksum = "34704c8d6ebcbc939824180af020566b01a7c01f80641264eba0999f6c2b6be7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
 ]
 
 [[package]]
@@ -3446,7 +3432,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
  "wasm-bindgen-shared",
 ]
 
@@ -3468,7 +3454,7 @@ checksum = "f0eb82fcb7930ae6219a7ecfd55b217f5f0893484b7a13022ebb2b2bf20b5283"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.40",
+ "syn 2.0.60",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
diff --git a/cargo-geiger/Cargo.toml b/cargo-geiger/Cargo.toml
index 7c3b11fc..2311e098 100644
--- a/cargo-geiger/Cargo.toml
+++ b/cargo-geiger/Cargo.toml
@@ -17,7 +17,7 @@ maintenance = { status = "experimental" }
 anyhow = "1.0.70"
 cargo = "0.75.1"
 cargo-geiger-serde = { path = "../cargo-geiger-serde", version = "0.2.3" }
-cargo_metadata = "0.18.1"
+cargo_metadata = "0.15.4"
 cargo-platform = "0.1.2"
 colored = "2.0.0"
 console = "0.15.5"
diff --git a/cargo-geiger/src/mapping/geiger.rs b/cargo-geiger/src/mapping/geiger.rs
index 2f40ce0f..978ede71 100644
--- a/cargo-geiger/src/mapping/geiger.rs
+++ b/cargo-geiger/src/mapping/geiger.rs
@@ -114,10 +114,10 @@ mod geiger_tests {
             }
         ),
         case(
-            "git+https://github.com/rust-itertools/itertools.git?rev=8761fbefb3b209",
+            "git+https://github.com/rust-itertools/itertools.git?rev=98d3978",
             CargoGeigerSerdeSource::Git {
                 url: Url::parse("https://github.com/rust-itertools/itertools.git").unwrap(),
-                rev: String::from("8761fbefb3b209")
+                rev: String::from("98d3978")
             }
         ),
         case(
diff --git a/cargo-geiger/src/scan/rs_file/custom_executor.rs b/cargo-geiger/src/scan/rs_file/custom_executor.rs
index f8402894..bffbb657 100644
--- a/cargo-geiger/src/scan/rs_file/custom_executor.rs
+++ b/cargo-geiger/src/scan/rs_file/custom_executor.rs
@@ -27,9 +27,13 @@ pub struct CustomExecutor {
 
 #[derive(Debug)]
 enum CustomExecutorError {
+    #[allow(dead_code)]
     InnerContextMutex(String),
+    #[allow(dead_code)]
     Io(io::Error, PathBuf),
+    #[allow(dead_code)]
     OutDirKeyMissing(String),
+    #[allow(dead_code)]
     OutDirValueMissing(String),
 }
 
diff --git a/cargo-geiger/tests/external_package_reports/mod.rs b/cargo-geiger/tests/external_package_reports/mod.rs
index 006aa7a7..1acfc25d 100644
--- a/cargo-geiger/tests/external_package_reports/mod.rs
+++ b/cargo-geiger/tests/external_package_reports/mod.rs
@@ -114,11 +114,11 @@ pub fn doc_comment_safety_report() -> SafetyReport {
 pub fn itertools_package_id() -> PackageId {
     PackageId {
         name: "itertools".into(),
-        version: Version::new(0, 8, 0),
+        version: Version::new(0, 12, 1),
         source: Source::Git {
             url: Url::parse("https://github.com/rust-itertools/itertools.git")
                 .unwrap(),
-            rev: "8761fbefb3b209".into(),
+            rev: "98d3978".into(),
         },
     }
 }
diff --git a/cargo-geiger/tests/integration_tests.rs b/cargo-geiger/tests/integration_tests.rs
index 1b8e9e62..265f9d04 100644
--- a/cargo-geiger/tests/integration_tests.rs
+++ b/cargo-geiger/tests/integration_tests.rs
@@ -35,7 +35,7 @@ fn test_package(name: &str) {
     if !stderr.is_empty() {
         let manifest_path_regex = regex::Regex::new(r"`([^`]+).toml`").unwrap();
         let artifact_json_blob_regex =
-            regex::Regex::new(r#"\{"artifact":.*"emit":.*\}"#).unwrap();
+            regex::Regex::new(r#"\{"\$message_type":"artifact","artifact":.*"emit":.*\}"#).unwrap();
 
         let stderr = manifest_path_regex.replace(&stderr, "`{MANIFEST_PATH}`");
         let stderr = artifact_json_blob_regex
diff --git a/cargo-geiger/tests/snapshots/integration_tests__test3_package_with_nested_deps.stdout.snap b/cargo-geiger/tests/snapshots/integration_tests__test3_package_with_nested_deps.stdout.snap
index 96751aa1..31be33fc 100644
--- a/cargo-geiger/tests/snapshots/integration_tests__test3_package_with_nested_deps.stdout.snap
+++ b/cargo-geiger/tests/snapshots/integration_tests__test3_package_with_nested_deps.stdout.snap
@@ -16,12 +16,12 @@ Functions  Expressions  Impls  Traits  Methods  Dependency
 
 0/0        1/1          0/0    0/0     0/0      !  test3_package_with_nested_deps 0.1.0
 0/0        0/0          0/0    0/0     0/0      ?  ├── doc-comment 0.3.1
-0/0        0/72         0/3    0/1     0/3      ?  ├── itertools 0.8.0
+0/0        13/83        0/3    0/1     0/3      !  ├── itertools 0.12.1
 0/0        0/0          0/0    0/0     0/0      ?  │   └── either 1.5.2
 1/1        4/4          0/0    0/0     0/0      !  └── test2_package_with_shallow_deps 0.1.0
 0/0        2/2          0/0    0/0     0/0      !      ├── ref_slice 1.1.1
 1/1        2/2          0/0    0/0     0/0      !      └── test1_package_with_no_deps 0.1.0
 
-2/2        9/81         0/3    0/1     0/3    
+2/2        22/92        0/3    0/1     0/3
 
 
diff --git a/cargo-geiger/tests/snapshots/integration_tests__test6_cargo_lock_out_of_date.stdout.snap b/cargo-geiger/tests/snapshots/integration_tests__test6_cargo_lock_out_of_date.stdout.snap
index 2ad3825a..8b6bd0a4 100644
--- a/cargo-geiger/tests/snapshots/integration_tests__test6_cargo_lock_out_of_date.stdout.snap
+++ b/cargo-geiger/tests/snapshots/integration_tests__test6_cargo_lock_out_of_date.stdout.snap
@@ -22,8 +22,8 @@ Functions  Expressions  Impls  Traits  Methods  Dependency
 0/0        0/0          0/0    0/0     0/0      :)     ├── unicode-bidi 0.3.4
 0/0        0/0          0/0    0/0     0/0      ?      │   └── matches 0.1.8
 0/0        20/20        0/0    0/0     0/0      !      └── unicode-normalization 0.1.8
-2/2        354/354      4/4    1/1     13/13    !          └── smallvec 0.6.9
+2/2        349/349      4/4    1/1     13/13    !          └── smallvec 0.6.9
 
-2/2        375/375      4/4    1/1     13/13  
+2/2        370/370      4/4    1/1     13/13
 
 
diff --git a/cargo-geiger/tests/snapshots/integration_tests__test9_package_with_git_deps.stdout.snap b/cargo-geiger/tests/snapshots/integration_tests__test9_package_with_git_deps.stdout.snap
index acc8f890..a6c99d2f 100644
--- a/cargo-geiger/tests/snapshots/integration_tests__test9_package_with_git_deps.stdout.snap
+++ b/cargo-geiger/tests/snapshots/integration_tests__test9_package_with_git_deps.stdout.snap
@@ -15,10 +15,10 @@ Symbols:
 Functions  Expressions  Impls  Traits  Methods  Dependency
 
 0/0        0/0          0/0    0/0     0/0      ?  test9_package_with_git_deps 0.1.0
-0/0        0/72         0/3    0/1     0/3      ?  ├── itertools 0.8.0
-0/0        14/14        0/0    0/0     0/0      !  │   └── either 1.9.0
+0/0        13/83        0/3    0/1     0/3      !  ├── itertools 0.12.1
+0/0        14/14        0/0    0/0     0/0      !  │   └── either 1.11.0
 0/0        2/2          0/0    0/0     0/0      !  └── ref_slice 1.2.1
 
-0/0        16/88        0/3    0/1     0/3    
+0/0        29/99        0/3    0/1     0/3
 
 
diff --git a/cargo-geiger/tests/snapshots/readme_integration_tests__test3_package_with_nested_deps.readme.snap b/cargo-geiger/tests/snapshots/readme_integration_tests__test3_package_with_nested_deps.readme.snap
index 0b319960..9b96ba6b 100644
--- a/cargo-geiger/tests/snapshots/readme_integration_tests__test3_package_with_nested_deps.readme.snap
+++ b/cargo-geiger/tests/snapshots/readme_integration_tests__test3_package_with_nested_deps.readme.snap
@@ -24,13 +24,13 @@ Functions  Expressions  Impls  Traits  Methods  Dependency
 
 0/0        1/1          0/0    0/0     0/0      ☢️  test3_package_with_nested_deps 0.1.0
 0/0        0/0          0/0    0/0     0/0      ❓  ├── doc-comment 0.3.1
-0/0        0/72         0/3    0/1     0/3      ❓  ├── itertools 0.8.0
+0/0        13/83        0/3    0/1     0/3      ☢️  ├── itertools 0.12.1
 0/0        0/0          0/0    0/0     0/0      ❓  │   └── either 1.5.2
 1/1        4/4          0/0    0/0     0/0      ☢️  └── test2_package_with_shallow_deps 0.1.0
 0/0        2/2          0/0    0/0     0/0      ☢️      ├── ref_slice 1.1.1
 1/1        2/2          0/0    0/0     0/0      ☢️      └── test1_package_with_no_deps 0.1.0
 
-2/2        9/81         0/3    0/1     0/3    
+2/2        22/92        0/3    0/1     0/3    
 
 ```
 ## Second Section Header
diff --git a/cargo-geiger/tests/snapshots/readme_integration_tests__test6_cargo_lock_out_of_date.readme.snap b/cargo-geiger/tests/snapshots/readme_integration_tests__test6_cargo_lock_out_of_date.readme.snap
index 2d249579..36a76336 100644
--- a/cargo-geiger/tests/snapshots/readme_integration_tests__test6_cargo_lock_out_of_date.readme.snap
+++ b/cargo-geiger/tests/snapshots/readme_integration_tests__test6_cargo_lock_out_of_date.readme.snap
@@ -24,9 +24,9 @@ Functions  Expressions  Impls  Traits  Methods  Dependency
 0/0        0/0          0/0    0/0     0/0      🔒      ├── unicode-bidi 0.3.4
 0/0        0/0          0/0    0/0     0/0      ❓      │   └── matches 0.1.8
 0/0        20/20        0/0    0/0     0/0      ☢️      └── unicode-normalization 0.1.8
-2/2        354/354      4/4    1/1     13/13    ☢️          └── smallvec 0.6.9
+2/2        349/349      4/4    1/1     13/13    ☢️          └── smallvec 0.6.9
 
-2/2        375/375      4/4    1/1     13/13  
+2/2        370/370      4/4    1/1     13/13  
 
 ```
 
diff --git a/geiger/Cargo.toml b/geiger/Cargo.toml
index cec60c0b..73d99803 100644
--- a/geiger/Cargo.toml
+++ b/geiger/Cargo.toml
@@ -15,7 +15,7 @@ maintenance = { status = "experimental" }
 
 [dependencies]
 cargo-geiger-serde = { path = "../cargo-geiger-serde", version = "0.2.3" }
-syn = { version = "1.0.109", features = ["parsing", "printing", "clone-impls", "full", "extra-traits", "visit"] }
+syn = { version = "^2.0.60", features = ["parsing", "printing", "clone-impls", "full", "extra-traits", "visit"] }
 proc-macro2 = "1.0.78"
 
 [dev-dependencies]
diff --git a/geiger/src/find.rs b/geiger/src/find.rs
index f5981e5e..c5b5fd7c 100644
--- a/geiger/src/find.rs
+++ b/geiger/src/find.rs
@@ -38,14 +38,24 @@ mod find_tests {
     use super::*;
 
     use cargo_geiger_serde::{Count, CounterBlock};
-    use rstest::*;
-    use std::io::Write;
     use tempfile::tempdir;
 
+    const DEFAULT_COUNTERS: CounterBlock = CounterBlock {
+        functions: Count { safe: 0, unsafe_: 0 },
+        exprs: Count { safe: 0, unsafe_: 0 },
+        item_impls: Count { safe: 0, unsafe_: 0 },
+        item_traits: Count { safe: 0, unsafe_: 0 },
+        methods: Count { safe: 0, unsafe_: 0 },
+    };
+    const DEFAULT_METRICS: RsFileMetrics = RsFileMetrics {
+        counters: DEFAULT_COUNTERS,
+        forbids_unsafe: false,
+    };
+
     const FILE_CONTENT_STRING: &str = "use std::io::Write;
 
 pub unsafe fn f() {
-    unimplemented!()
+    f();
 }
 
 pub fn g() {
@@ -56,12 +66,12 @@ pub fn g() {
 
 #[no_mangle]
 pub fn h() {
-    unimplemented!()
+    f();
 }
 
 #[export_name = \"exported_g\"]
 pub fn g() {
-    unimplemented!()
+    f();
 }
 
 #[cfg(test)]
@@ -71,162 +81,138 @@ mod tests {
     #[test]
     fn test_1() {
         unsafe {
-            println!(\"Inside unsafe\");
+            f();
         }
     }
 }
 ";
 
-    #[rstest(
-        input_include_tests,
-        expected_rs_file_metrics,
-        case(
-        IncludeTests::Yes,
-        RsFileMetrics {
+    #[test]
+    fn find_unsafe() {
+        let temp_dir = tempdir().unwrap();
+        let file_path = temp_dir.path().join("lib.rs");
+        std::fs::write(&file_path, FILE_CONTENT_STRING).unwrap();
+
+        let from_file =
+            find_unsafe_in_file(&file_path, IncludeTests::No).unwrap();
+        let from_string =
+            find_unsafe_in_string(FILE_CONTENT_STRING, IncludeTests::No).unwrap();
+        let expected = RsFileMetrics {
             counters: CounterBlock {
-                functions: Count {
-                    safe: 2,
-                    unsafe_: 3
-                },
-                exprs: Count {
-                    safe: 4,
-                    unsafe_: 5
-                },
-                item_impls: Count {
-                    safe: 0,
-                    unsafe_: 0
-                },
-                item_traits: Count {
-                    safe: 0,
-                    unsafe_: 0
-                },
-                methods: Count {
-                    safe: 0,
-                    unsafe_: 0
-                }
+                functions: Count { safe: 1, unsafe_: 3 },
+                exprs: Count { safe: 4, unsafe_: 4 },
+                ..DEFAULT_COUNTERS
             },
-            forbids_unsafe: false
-        }
-        ),
-        case(
-            IncludeTests::No,
-            RsFileMetrics {
-                counters: CounterBlock {
-                    functions: Count {
-                        safe: 1,
-                        unsafe_: 3
-                    },
-                    exprs: Count {
-                        safe: 4,
-                        unsafe_: 4
-                    },
-                    item_impls: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    },
-                    item_traits: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    },
-                    methods: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    }
-                },
-                forbids_unsafe: false
-            }
-        )
-    )]
-    fn find_unsafe_in_file_test_no_errors(
-        input_include_tests: IncludeTests,
-        expected_rs_file_metrics: RsFileMetrics,
-    ) {
-        let temp_dir = tempdir().unwrap();
-        let lib_file_path = temp_dir.path().join("lib.rs");
-        let mut file = File::create(lib_file_path.clone()).unwrap();
-
-        writeln!(file, "{}", FILE_CONTENT_STRING).unwrap();
-
-        let unsafe_in_file_result =
-            find_unsafe_in_file(&lib_file_path, input_include_tests);
+            ..DEFAULT_METRICS
+        };
+        assert_eq!(from_file, expected);
+        assert_eq!(from_string, expected);
+
+        let from_file =
+            find_unsafe_in_file(&file_path, IncludeTests::Yes).unwrap();
+        let from_string =
+            find_unsafe_in_string(FILE_CONTENT_STRING, IncludeTests::Yes).unwrap();
+        let expected = RsFileMetrics {
+            counters: CounterBlock {
+                functions: Count { safe: 2, unsafe_: 3 },
+                exprs: Count { safe: 4, unsafe_: 5 },
+                ..DEFAULT_COUNTERS
+            },
+            ..DEFAULT_METRICS
+        };
+        assert_eq!(from_file, expected);
+        assert_eq!(from_string, expected);
+    }
 
-        assert!(unsafe_in_file_result.is_ok());
+    #[test]
+    fn forbids_unsafe() {
+        let expected = RsFileMetrics { forbids_unsafe: true, ..DEFAULT_METRICS };
+        let actual = find_unsafe_in_string("#![forbid(unsafe_code)]", IncludeTests::No).unwrap();
+        assert_eq!(actual, expected);
+    }
 
-        let unsafe_in_file = unsafe_in_file_result.unwrap();
+    #[test]
+    fn counters_functions() {
+        let expected = RsFileMetrics {
+            counters: CounterBlock {
+                functions: Count { safe: 2, unsafe_: 3 },
+                exprs: Count { safe: 2, unsafe_: 3 },
+                ..DEFAULT_COUNTERS
+            },
+            ..DEFAULT_METRICS
+        };
+        let file = "
+            pub fn f() { f(); }
+            pub fn f() { f(); }
+            pub unsafe fn f() { f(); }
+            #[no_mangle]
+            pub fn f() { f(); }
+            #[export_name = \"exported_e\"]
+            pub unsafe fn f() { f(); }
+        ";
+        let actual = find_unsafe_in_string(file, IncludeTests::No).unwrap();
+        assert_eq!(actual, expected);
+    }
 
-        assert_eq!(unsafe_in_file, expected_rs_file_metrics);
+    #[test]
+    fn counters_exprs() {
+        let file = "
+            pub fn f() {
+                f();
+                x.f();
+                let x = *y;
+                println!(\"abc\"); // The `syn` crate v2.0.60 doesn't visit macros.
+                let x = 1; // Literal expressions are not counted.
+            }
+            pub fn f() { unsafe { let x = f(); } }
+            pub unsafe fn f() { let x = f(); }
+            #[cfg(test)]
+            mod tests {
+                pub fn f() { f(); }
+            }
+            #[test]
+            pub fn f() { f(); }
+        ";
+        let expected = RsFileMetrics {
+            counters: CounterBlock {
+                functions: Count { safe: 2, unsafe_: 1 },
+                exprs: Count { safe: 3, unsafe_: 2 },
+                ..DEFAULT_COUNTERS
+            },
+            ..DEFAULT_METRICS
+        };
+        let actual = find_unsafe_in_string(file, IncludeTests::No).unwrap();
+        assert_eq!(actual, expected);
     }
 
-    #[rstest(
-        input_include_tests,
-        expected_rs_file_metrics,
-        case(
-            IncludeTests::Yes,
-            RsFileMetrics {
-                counters: CounterBlock {
-                    functions: Count {
-                        safe: 2,
-                        unsafe_: 3
-                    },
-                    exprs: Count {
-                        safe: 4,
-                        unsafe_: 5
-                    },
-                    item_impls: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    },
-                    item_traits: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    },
-                    methods: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    }
-                },
-                forbids_unsafe: false
+    #[test]
+    fn counters_exprs_include_tests() {
+        let file = "
+            pub fn f() { f(); }
+            pub unsafe fn f() { f(); }
+            #[cfg(test)]
+            mod tests {
+                pub unsafe fn f() { f(); }
+                pub fn f() {
+                    f();
+                    unsafe { f(); }
+                }
             }
-        ),
-        case(
-            IncludeTests::No,
-            RsFileMetrics {
-                counters: CounterBlock {
-                    functions: Count {
-                        safe: 1,
-                        unsafe_: 3
-                    },
-                    exprs: Count {
-                        safe: 4,
-                        unsafe_: 4
-                    },
-                    item_impls: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    },
-                    item_traits: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    },
-                    methods: Count {
-                        safe: 0,
-                        unsafe_: 0
-                    }
-                },
-                forbids_unsafe: false
+            #[test]
+            pub fn f() {
+                f();
+                unsafe { f(); }
             }
-        )
-    )]
-    fn find_unsafe_in_string_test(
-        input_include_tests: IncludeTests,
-        expected_rs_file_metrics: RsFileMetrics,
-    ) {
-        let unsafe_in_string_result =
-            find_unsafe_in_string(FILE_CONTENT_STRING, input_include_tests);
-
-        assert!(unsafe_in_string_result.is_ok());
-        let unsafe_in_string = unsafe_in_string_result.unwrap();
-
-        assert_eq!(unsafe_in_string, expected_rs_file_metrics);
+        ";
+        let expected = RsFileMetrics {
+            counters: CounterBlock {
+                functions: Count { safe: 3, unsafe_: 2 },
+                exprs: Count { safe: 3, unsafe_: 4 },
+                ..DEFAULT_COUNTERS
+            },
+            ..DEFAULT_METRICS
+        };
+        let actual = find_unsafe_in_string(file, IncludeTests::Yes).unwrap();
+        assert_eq!(actual, expected);
     }
 }
diff --git a/geiger/src/geiger_syn_visitor.rs b/geiger/src/geiger_syn_visitor.rs
index a9dea845..de83e655 100644
--- a/geiger/src/geiger_syn_visitor.rs
+++ b/geiger/src/geiger_syn_visitor.rs
@@ -3,7 +3,7 @@ use super::{
     IncludeTests, RsFileMetrics,
 };
 
-use syn::{visit, Expr, ImplItemMethod, ItemFn, ItemImpl, ItemMod, ItemTrait};
+use syn::{visit, Expr, ItemFn, ItemImpl, ItemMod, ItemTrait, ImplItemFn, ExprUnsafe};
 
 pub struct GeigerSynVisitor {
     /// Count unsafe usage inside tests
@@ -43,7 +43,7 @@ impl GeigerSynVisitor {
 impl<'ast> visit::Visit<'ast> for GeigerSynVisitor {
     fn visit_file(&mut self, i: &'ast syn::File) {
         self.metrics.forbids_unsafe = file_forbids_unsafe(i);
-        syn::visit::visit_file(self, i);
+        visit::visit_file(self, i);
     }
 
     /// Free-standing functions
@@ -66,25 +66,20 @@ impl<'ast> visit::Visit<'ast> for GeigerSynVisitor {
     fn visit_expr(&mut self, i: &Expr) {
         // Total number of expressions of any type
         match i {
-            Expr::Unsafe(i) => {
-                self.enter_unsafe_scope();
-                visit::visit_expr_unsafe(self, i);
-                self.exit_unsafe_scope();
+            Expr::Lit(..) | Expr::Path(..) | Expr::Unsafe(..) => {
+                // Do not count.
             }
-            Expr::Path(_) | Expr::Lit(_) => {
-                // Do not count. The expression `f(x)` should count as one
-                // expression, not three.
-            }
-            other => {
-                // TODO: Print something pretty here or gather the data for later
-                // printing.
-                // if self.verbosity == Verbosity::Verbose && self.unsafe_scopes > 0 {
-                //     println!("{:#?}", other);
-                // }
+            _ => {
                 self.metrics.counters.exprs.count(self.unsafe_scopes > 0);
-                visit::visit_expr(self, other);
             }
         }
+        visit::visit_expr(self, i);
+    }
+
+    fn visit_expr_unsafe(&mut self, i: &ExprUnsafe) {
+        self.enter_unsafe_scope();
+        visit::visit_expr_unsafe(self, i);
+        self.exit_unsafe_scope();
     }
 
     fn visit_item_mod(&mut self, i: &ItemMod) {
@@ -109,7 +104,7 @@ impl<'ast> visit::Visit<'ast> for GeigerSynVisitor {
         visit::visit_item_trait(self, i);
     }
 
-    fn visit_impl_item_method(&mut self, i: &ImplItemMethod) {
+    fn visit_impl_item_fn(&mut self, i: &ImplItemFn) {
         if i.sig.unsafety.is_some() {
             self.enter_unsafe_scope()
         }
@@ -117,7 +112,7 @@ impl<'ast> visit::Visit<'ast> for GeigerSynVisitor {
             .counters
             .methods
             .count(i.sig.unsafety.is_some());
-        visit::visit_impl_item_method(self, i);
+        visit::visit_impl_item_fn(self, i);
         if i.sig.unsafety.is_some() {
             self.exit_unsafe_scope()
         }
diff --git a/geiger/src/lib.rs b/geiger/src/lib.rs
index 98492bac..f166792c 100644
--- a/geiger/src/lib.rs
+++ b/geiger/src/lib.rs
@@ -18,7 +18,7 @@ use std::fmt;
 use std::io;
 use std::path::PathBuf;
 use std::string::FromUtf8Error;
-use syn::{ItemFn, ItemMod};
+use syn::{AttrStyle, ItemFn, ItemMod};
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum IncludeTests {
@@ -54,54 +54,44 @@ impl fmt::Display for ScanFileError {
 }
 
 fn file_forbids_unsafe(f: &syn::File) -> bool {
-    use syn::AttrStyle;
-    use syn::Meta;
-    use syn::MetaList;
-    use syn::NestedMeta;
-    f.attrs
-        .iter()
-        .filter(|a| matches!(a.style, AttrStyle::Inner(_)))
-        .filter_map(|a| a.parse_meta().ok())
-        .filter(|meta| match meta {
-            Meta::List(MetaList {
-                path,
-                paren_token: _paren,
-                nested,
-            }) => {
-                if !path.is_ident("forbid") {
-                    return false;
-                }
-                nested.iter().any(|n| match n {
-                    NestedMeta::Meta(Meta::Path(p)) => {
-                        p.is_ident("unsafe_code")
+    f.attrs.iter().any(|attr|{
+        // https://docs.rs/syn/latest/syn/meta/struct.ParseNestedMeta.html#example
+        let mut is_forbid_unsafe_code = false;
+        if matches!(attr.style, AttrStyle::Inner(_)) { // Parses `#!`.
+            if attr.path().is_ident("forbid") { // Parses `forbid`.
+                let _ = attr.parse_nested_meta(|meta| { // Parses `(`.
+                    if meta.path.is_ident("unsafe_code") {
+                        if meta.value().is_err() {
+                            is_forbid_unsafe_code = true;
+                        }
                     }
-                    _ => false,
-                })
+                    Ok(())
+                });
             }
-            _ => false,
-        })
-        .count()
-        > 0
+        }
+        is_forbid_unsafe_code
+    })
 }
 
 fn is_test_fn(item_fn: &ItemFn) -> bool {
-    use syn::Attribute;
     item_fn
         .attrs
         .iter()
-        .flat_map(Attribute::parse_meta)
-        .any(|m| meta_contains_ident(&m, "test"))
+        .any(|attr| attr.path().is_ident("test"))
 }
 
 fn has_unsafe_attributes(item_fn: &ItemFn) -> bool {
-    use syn::Attribute;
     item_fn
         .attrs
         .iter()
-        .flat_map(Attribute::parse_meta)
-        .any(|m| {
-            meta_contains_ident(&m, "no_mangle")
-                || meta_contains_attribute(&m, "export_name")
+        .any(|attr| {
+            if attr.path().is_ident("no_mangle") {
+                return true;
+            }
+            if attr.path().is_ident("export_name") {
+                return true;
+            }
+            false
         })
 }
 
@@ -112,56 +102,20 @@ fn has_unsafe_attributes(item_fn: &ItemFn) -> bool {
 /// every single source file path and span within each source file and use that
 /// as a general filter for included code.
 /// TODO: Investigate if the needed information can be emitted by rustc today.
-fn is_test_mod(i: &ItemMod) -> bool {
-    use syn::Attribute;
-    use syn::Meta;
-    i.attrs
+fn is_test_mod(item: &ItemMod) -> bool {
+    item
+        .attrs
         .iter()
-        .flat_map(Attribute::parse_meta)
-        .any(|m| match m {
-            Meta::List(ml) => meta_list_is_cfg_test(&ml),
-            _ => false,
+        .any(|attr| {
+            let mut found_cfg_test = false;
+            if attr.path().is_ident("cfg") {
+                let _ = attr.parse_nested_meta(|meta| { // Parse `(`.
+                    if meta.path.is_ident("test") {
+                        found_cfg_test = true;
+                    }
+                    Ok(())
+                });
+            }
+            found_cfg_test
         })
 }
-
-fn meta_contains_ident(m: &syn::Meta, ident: &str) -> bool {
-    use syn::Meta;
-    match m {
-        Meta::Path(p) => p.is_ident(ident),
-        _ => false,
-    }
-}
-
-fn meta_contains_attribute(m: &syn::Meta, ident: &str) -> bool {
-    use syn::Meta;
-    match m {
-        Meta::NameValue(nv) => nv.path.is_ident(ident),
-        _ => false,
-    }
-}
-
-// MetaList {
-//     ident: Ident(
-//         cfg
-//     ),
-//     paren_token: Paren,
-//     nested: [
-//         Meta(
-//             Word(
-//                 Ident(
-//                     test
-//                 )
-//             )
-//         )
-//     ]
-// }
-fn meta_list_is_cfg_test(meta_list: &syn::MetaList) -> bool {
-    use syn::NestedMeta;
-    if !meta_list.path.is_ident("cfg") {
-        return false;
-    }
-    meta_list.nested.iter().any(|n| match n {
-        NestedMeta::Meta(meta) => meta_contains_ident(meta, "test"),
-        _ => false,
-    })
-}
diff --git a/rust-toolchain b/rust-toolchain
new file mode 100644
index 00000000..38ab2bd6
--- /dev/null
+++ b/rust-toolchain
@@ -0,0 +1 @@
+1.76
\ No newline at end of file
diff --git a/test_crates/test3_package_with_nested_deps/Cargo.toml b/test_crates/test3_package_with_nested_deps/Cargo.toml
index 67872541..fc0b910d 100644
--- a/test_crates/test3_package_with_nested_deps/Cargo.toml
+++ b/test_crates/test3_package_with_nested_deps/Cargo.toml
@@ -5,5 +5,5 @@ edition = "2018"
 
 [dependencies]
 doc-comment = "0.3.1"
-itertools = { git = "https://github.com/rust-itertools/itertools.git", rev = "8761fbefb3b209" }
+itertools = { git = "https://github.com/rust-itertools/itertools.git", rev = "98d3978" }
 test2_package_with_shallow_deps = { path = "../test2_package_with_shallow_deps" }
diff --git a/test_crates/test9_package_with_git_deps/Cargo.toml b/test_crates/test9_package_with_git_deps/Cargo.toml
index 9ae6cea6..d880a0c3 100644
--- a/test_crates/test9_package_with_git_deps/Cargo.toml
+++ b/test_crates/test9_package_with_git_deps/Cargo.toml
@@ -5,5 +5,5 @@ edition = "2018"
 
 [dependencies]
 ref_slice = { git = "https://github.com/steveklabnik/ref_slice.git" }
-itertools = { git = "https://github.com/rust-itertools/itertools.git", rev = "8761fbefb3b209" }
+itertools = { git = "https://github.com/rust-itertools/itertools.git", rev = "98d3978" }
 [workspace]
\ No newline at end of file