diff --git a/dev/core/src/com/google/gwt/dev/javac/UnitCacheSingleton.java b/dev/core/src/com/google/gwt/dev/javac/UnitCacheSingleton.java
index 4d01f3e..fb272cd 100644
--- a/dev/core/src/com/google/gwt/dev/javac/UnitCacheSingleton.java
+++ b/dev/core/src/com/google/gwt/dev/javac/UnitCacheSingleton.java
@@ -57,7 +57,8 @@
         Md5Utils.getMd5Digest(
             Joiner.on('-').join(
                 options.getJsInteropExportFilter(),
-                options.shouldGenerateJsInteropExports()
+                options.shouldGenerateJsInteropExports(),
+                options.getSourceLevel()
         ).getBytes()));
   }