diff --git a/explorer/testdata/impl/impl_as.carbon b/explorer/testdata/impl/fail_impl_as.carbon
similarity index 78%
rename from explorer/testdata/impl/impl_as.carbon
rename to explorer/testdata/impl/fail_impl_as.carbon
index c80bfa9c3d2c..eb29d57fb4f1 100644
--- a/explorer/testdata/impl/impl_as.carbon
+++ b/explorer/testdata/impl/fail_impl_as.carbon
@@ -10,7 +10,7 @@
 
 package ExplorerTest api;
 
-// CHECK: COMPILATION ERROR: {{.*}}/explorer/testdata/impl/impl_as.carbon:[[@LINE+1]]: expected constraint after `as`, found value of type i32
+// CHECK: COMPILATION ERROR: {{.*}}/explorer/testdata/impl/fail_impl_as.carbon:[[@LINE+1]]: expected constraint after `as`, found value of type i32
 external impl i32 as i32 {}
 
 fn Main() -> i32 {