diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownThreadSafety.java b/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownThreadSafety.java
index b2e9eb4e0bf..60b3585c490 100644
--- a/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownThreadSafety.java
+++ b/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/WellKnownThreadSafety.java
@@ -67,6 +67,7 @@ private static ImmutableMap<String, AnnotationInfo> buildThreadSafeClasses(
         .add(java.lang.Thread.class)
         .add(java.time.InstantSource.class)
         .add(java.time.Clock.class)
+        .add(java.util.Properties.class)
         .add(java.util.Random.class)
         .add(java.util.concurrent.atomic.AtomicBoolean.class)
         .add(java.util.concurrent.atomic.AtomicInteger.class)