diff --git a/Cargo.lock b/Cargo.lock
index 0153b466..36076b34 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -148,6 +148,16 @@ version = "0.8.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e496a50fda8aacccc86d7529e2c1e0892dbd0f898a6b5645b5561b89c3210efa"
 
+[[package]]
+name = "ctor"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37e366bff8cd32dd8754b0991fb66b279dc48f598c3a18914852a6673deef583"
+dependencies = [
+ "quote",
+ "syn 2.0.37",
+]
+
 [[package]]
 name = "deluxe"
 version = "0.5.0"
@@ -944,6 +954,7 @@ name = "kooha"
 version = "2.2.4"
 dependencies = [
  "anyhow",
+ "ctor",
  "futures-channel",
  "futures-util",
  "gdk4-wayland",
diff --git a/Cargo.toml b/Cargo.toml
index 4c52b5f8..1afda950 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,3 +29,6 @@ futures-util = { version = "0.3", default-features = false }
 gsettings-macro = "0.1.15"
 pulse = { package = "libpulse-binding", version = "2.26.0" }
 pulse_glib = { package = "libpulse-glib-binding", version = "2.25.1" }
+
+[dev-dependencies]
+ctor = "0.2.5"
diff --git a/src/main.rs b/src/main.rs
index c05eef05..a8b47781 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -51,6 +51,10 @@ use self::{
     config::{GETTEXT_PACKAGE, LOCALEDIR, RESOURCES_FILE},
 };
 
+#[cfg(test)]
+#[macro_use]
+extern crate ctor;
+
 fn main() -> glib::ExitCode {
     tracing_subscriber::fmt::init();
 
@@ -70,3 +74,32 @@ fn main() -> glib::ExitCode {
     let app = Application::new();
     app.run()
 }
+
+#[cfg(test)]
+mod test {
+    use ctor;
+    use std::{env, process::Command};
+
+    // Run once before tests are executed.
+    #[ctor]
+    fn setup_schema() {
+        let schema_dir = &env::var("GSETTINGS_SCHEMA_DIR")
+            .unwrap_or(concat!(env!("CARGO_MANIFEST_DIR"), "/data").into());
+
+        let output = Command::new("glib-compile-schemas")
+            .arg(schema_dir)
+            .output()
+            .unwrap();
+
+        if !output.status.success() {
+            panic!(
+                "Failed to compile GSchema for tests; stdout: {}; stderr: {}",
+                String::from_utf8_lossy(&output.stdout),
+                String::from_utf8_lossy(&output.stderr)
+            );
+        }
+
+        env::set_var("GSETTINGS_SCHEMA_DIR", schema_dir);
+        env::set_var("GSETTINGS_BACKEND", "memory");
+    }
+}
diff --git a/src/meson.build b/src/meson.build
index 002cc1f5..ae0fde16 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -59,9 +59,11 @@ test(
     cargo_options,
     '--',
     '--nocapture',
+    '--test-threads=1',
   ],
   env: [
     'RUST_BACKTRACE=1',
+    'GSETTINGS_SCHEMA_DIR=@0@/data'.format(meson.project_build_root()),
     cargo_env
   ],
   timeout: 300, # give cargo more time
diff --git a/src/settings.rs b/src/settings.rs
index 8582a8ab..4d1c2bfc 100644
--- a/src/settings.rs
+++ b/src/settings.rs
@@ -150,36 +150,8 @@ impl Settings {
 mod tests {
     use super::*;
 
-    use std::{env, process::Command, sync::Once};
-
-    fn setup_schema() {
-        static INIT: Once = Once::new();
-
-        INIT.call_once(|| {
-            let schema_dir = concat!(env!("CARGO_MANIFEST_DIR"), "/data");
-
-            let output = Command::new("glib-compile-schemas")
-                .arg(schema_dir)
-                .output()
-                .unwrap();
-
-            if !output.status.success() {
-                panic!(
-                    "Failed to compile GSchema for tests; stdout: {}; stderr: {}",
-                    String::from_utf8_lossy(&output.stdout),
-                    String::from_utf8_lossy(&output.stderr)
-                );
-            }
-
-            env::set_var("GSETTINGS_SCHEMA_DIR", schema_dir);
-            env::set_var("GSETTINGS_BACKEND", "memory");
-        });
-    }
-
     #[test]
     fn default_profile() {
-        setup_schema();
-
         assert!(Settings::default().profile().is_some());
         assert!(Settings::default().profile().unwrap().supports_audio());
     }