diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..ddf2c8f
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,42 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  test:
+    name: "Build and test"
+    runs-on: ubuntu-latest
+    continue-on-error: false
+    strategy:
+      fail-fast: false
+      matrix:
+        php: ['8.3', '8.4', '8.5']
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          tools: phpize
+
+      - name: Set up
+        run: phpize
+
+      - name: Configure
+        run: ./configure --enable-custom_cast
+
+      - name: Make and install
+        run: sudo make -j"$(nproc)" install
+  
+      - name: Run tests
+        run: >-
+          REPORT_EXIT_STATUS=1
+          NO_INTERACTION=1
+          TEST_PHP_EXECUTABLE=$(which php)
+          php run-tests.php -n --show-diff tests
diff --git a/custom_cast.c b/custom_cast.c
index d0c2a30..f59e056 100644
--- a/custom_cast.c
+++ b/custom_cast.c
@@ -267,25 +267,22 @@ static zend_result custom_cast_do_cast(
 /**
  * Ensure that the flags for a class entry correspond to a userland class
  */
-static void require_user_class(uint32_t flags) {
+static const char* require_user_class(uint32_t flags) {
 	// Must actually be on a class
 	if (flags & ZEND_ACC_ENUM) {
-		zend_error_noreturn(E_ERROR, "Cannot apply #[CustomCasting\\CustomCastable] to enum");
+		return "Cannot apply #[CustomCasting\\CustomCastable] to enum";
 	}
 	if (flags & ZEND_ACC_INTERFACE) {
-		zend_error_noreturn(E_ERROR, "Cannot apply #[CustomCasting\\CustomCastable] to interface");
+		return "Cannot apply #[CustomCasting\\CustomCastable] to interface";
 	}
 	if (flags & ZEND_ACC_TRAIT) {
-		zend_error_noreturn(E_ERROR, "Cannot apply #[CustomCasting\\CustomCastable] to trait");
+		return "Cannot apply #[CustomCasting\\CustomCastable] to trait";
 	}
 	// Use ce->type != ZEND_INTERNAL_CLASS
 	if (flags & ZEND_ACC_LINKED) {
-		zend_error_noreturn(
-			E_ERROR,
-			"#[CustomCasting\\CustomCastable] is for user classes, internal classes can set a custom cast handler"
-		);
+		return "#[CustomCasting\\CustomCastable] is for user classes, internal classes can set a custom cast handler";
 	}
-
+	return NULL;
 }
 
 /**
@@ -378,12 +375,27 @@ static void ensure_class_has_interface(zend_class_entry *scope) {
 	scope->interface_names = newInterfaceSet;
 }
 
+#if PHP_VERSION_ID < 80500
 static void validate_custom_castable(
 		zend_attribute *attr, uint32_t target, zend_class_entry *scope)
+#else
+static zend_string *validate_custom_castable(
+		zend_attribute *attr, uint32_t target, zend_class_entry *scope)
+#endif
 {
-	require_user_class(scope->ce_flags);
+	const char *error = require_user_class(scope->ce_flags);
+	if (error != NULL) {
+#if PHP_VERSION_ID < 80500
+		zend_error_noreturn(E_ERROR, error);
+#else
+		return zend_string_init(error, strlen(error), 0);
+#endif
+	}
 	ensure_class_has_interface(scope);
 	scope->default_object_handlers = &custom_cast_obj_handlers;
+#if PHP_VERSION_ID >= 80500
+		return NULL;
+#endif
 }
 
 static void setup_CustomCastable_as_attribute(zend_class_entry *class_entry) {
diff --git a/tests/attribute_on_wrong/attribute_on_class_missing.phpt b/tests/attribute_on_wrong/attribute_on_class_missing.phpt
index 6c8577c..6849b21 100644
--- a/tests/attribute_on_wrong/attribute_on_class_missing.phpt
+++ b/tests/attribute_on_wrong/attribute_on_class_missing.phpt
@@ -13,4 +13,4 @@ class Demo {
 
 ?>
 --EXPECTF--
-Fatal error: Class Demo contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (CustomCasting\HasCustomCast::__doCast) in %s on line %d
\ No newline at end of file
+Fatal error: Class Demo contains 1 abstract method and must therefore be declared abstract or implement the remaining method%rs?%r (CustomCasting\HasCustomCast::__doCast) in %s on line %d
\ No newline at end of file