diff --git a/src/main/java/com/android/tools/r8/shaking/Enqueuer.java b/src/main/java/com/android/tools/r8/shaking/Enqueuer.java
index d377362..f6d9e6e 100644
--- a/src/main/java/com/android/tools/r8/shaking/Enqueuer.java
+++ b/src/main/java/com/android/tools/r8/shaking/Enqueuer.java
@@ -156,6 +156,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.function.BiConsumer;
@@ -3065,7 +3066,7 @@
 
     private final ProcessorContext processorContext;
     private Map<DexMethod, MethodProcessingContext> methodProcessingContexts =
-        new IdentityHashMap<>();
+        new ConcurrentHashMap<>();
 
     List<ProgramMethod> desugaredMethods = new LinkedList<>();