diff --git a/tests/DeferredCanvasTest.cpp b/tests/DeferredCanvasTest.cpp
index 1e7725d..8a834be 100644
--- a/tests/DeferredCanvasTest.cpp
+++ b/tests/DeferredCanvasTest.cpp
@@ -400,7 +400,7 @@
         }
     }
     // All cached resources should be evictable since last canvas call was flush()
-    canvas.freeMemoryIfPossible(~0);
+    canvas.freeMemoryIfPossible(~0U);
     REPORTER_ASSERT(reporter, 0 == canvas.storageAllocatedForRecording());
 }