diff --git a/src/Sniffs/AbstractPatternSniff.php b/src/Sniffs/AbstractPatternSniff.php
index e895365688..d9528dccf8 100644
--- a/src/Sniffs/AbstractPatternSniff.php
+++ b/src/Sniffs/AbstractPatternSniff.php
@@ -416,6 +416,11 @@ protected function processPattern($patternInfo, File $phpcsFile, $stackPtr)
         $lastAddedStackPtr = null;
         $patternLen        = count($pattern);
 
+        if (($stackPtr + $patternLen - $patternInfo['listen_pos']) > $phpcsFile->numTokens) {
+            // Pattern can never match as there are not enough tokens left in the file.
+            return false;
+        }
+
         for ($i = $patternInfo['listen_pos']; $i < $patternLen; $i++) {
             if (isset($tokens[$stackPtr]) === false) {
                 break;
diff --git a/src/Standards/Squiz/Tests/Functions/FunctionDeclarationUnitTest.2.inc b/src/Standards/Squiz/Tests/Functions/FunctionDeclarationUnitTest.2.inc
new file mode 100644
index 0000000000..51a55e92ad
--- /dev/null
+++ b/src/Standards/Squiz/Tests/Functions/FunctionDeclarationUnitTest.2.inc
@@ -0,0 +1,5 @@
+<?php
+
+// Intentional parse error. This has to be the last (and only) test in the file.
+// Live coding test. The sniff should stay silent.
+function
diff --git a/src/Standards/Squiz/Tests/Functions/FunctionDeclarationUnitTest.3.inc b/src/Standards/Squiz/Tests/Functions/FunctionDeclarationUnitTest.3.inc
new file mode 100644
index 0000000000..f14db70891
--- /dev/null
+++ b/src/Standards/Squiz/Tests/Functions/FunctionDeclarationUnitTest.3.inc
@@ -0,0 +1,5 @@
+<?php
+
+// Intentional parse error. This has to be the last (and only) test in the file.
+// Live coding test. The sniff should stay silent.
+function // Comment.