diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownMutability.java b/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownMutability.java
index 11b8c17a6ea..2babde7154f 100644
--- a/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownMutability.java
+++ b/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownMutability.java
@@ -204,6 +204,7 @@ private static ImmutableMap<String, AnnotationInfo> buildImmutableClasses(
         .add("java.util.OptionalDouble")
         .add("java.util.OptionalInt")
         .add("java.util.OptionalLong")
+        .add("java.time.Clock")
         .add("java.time.Duration")
         .add("java.time.Instant")
         .add("java.time.LocalDate")