diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/checkreturnvalue/ProtoRules.java b/core/src/main/java/com/google/errorprone/bugpatterns/checkreturnvalue/ProtoRules.java
index a21d48fcb62..fb5f8baac24 100644
--- a/core/src/main/java/com/google/errorprone/bugpatterns/checkreturnvalue/ProtoRules.java
+++ b/core/src/main/java/com/google/errorprone/bugpatterns/checkreturnvalue/ProtoRules.java
@@ -50,7 +50,7 @@ public static ResultUseRule<VisitorState, Symbol> protoBuilders() {
    */
   public static ResultUseRule<VisitorState, Symbol> mutableProtos() {
     return new ProtoRule(
-        isDescendantOfAny(ImmutableSet.of("com.google.protobuf.AbstractMutableMessageLite")),
+        isDescendantOfAny(ImmutableSet.of("com.google.protobuf.MutableMessageLite")),
         "MUTABLE_PROTO");
   }