diff --git a/core/src/main/java/org/jruby/anno/AnnotationHelper.java b/core/src/main/java/org/jruby/anno/AnnotationHelper.java
index 1047cb37cba..96fb4bfe0e8 100644
--- a/core/src/main/java/org/jruby/anno/AnnotationHelper.java
+++ b/core/src/main/java/org/jruby/anno/AnnotationHelper.java
@@ -112,6 +112,11 @@ public static void populateMethodIndex(Map<Set<FrameField>, List<String>> access
                 for (String name : names) {
                     if (uniqueValues.add(name)) {
                         joiner.add(name);
+
+                        // in order to support these names aliased with "!" we eagerly add those names as well (jruby/jruby#8200)
+                        if (name.matches("^[a-z_]+$")) {
+                            joiner.add(name + '!');
+                        }
                     }
                 }
                 String namesJoined = joiner.toString();