diff --git a/src/lib/diff-classifier.js b/src/lib/diff-classifier.js
index 5b0cafb..e729879 100644
--- a/src/lib/diff-classifier.js
+++ b/src/lib/diff-classifier.js
@@ -28,7 +28,7 @@ export const LOCK_FILES = new Set([
  */
 const CODE_BEARING_EXTS = new Set([
   '.ts', '.tsx', '.js', '.jsx', '.mjs', '.cjs',
-  '.py', '.go', '.rs', '.rb', '.java', '.kt', '.swift',
+  '.py', '.go', '.rs', '.rb', '.java', '.kt', '.swift', '.php'
 ]);
 
 /**
diff --git a/tests/diff-classifier.test.js b/tests/diff-classifier.test.js
index 12af206..964eeea 100644
--- a/tests/diff-classifier.test.js
+++ b/tests/diff-classifier.test.js
@@ -33,7 +33,7 @@ describe('diff-classifier', () => {
     });
 
     it('returns false for a single code-bearing file', () => {
-      const exts = ['.ts', '.tsx', '.js', '.jsx', '.mjs', '.cjs', '.py', '.go', '.rs', '.rb', '.java', '.kt', '.swift'];
+      const exts = ['.ts', '.tsx', '.js', '.jsx', '.mjs', '.cjs', '.py', '.go', '.rs', '.rb', '.java', '.kt', '.swift', '.php'];
       for (const ext of exts) {
         expect(isNoOpDiff([`src/file${ext}`])).toBe(false);
       }