diff --git a/include/core/SkShader.h b/include/core/SkShader.h
index 1515118..e9911ce 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -403,7 +403,7 @@
      *  If the shader is a custom shader which has data the caller might want, call this function
      *  to get that data.
      */
-    virtual bool asACustomShader(void** customData) const { return false; }
+    virtual bool asACustomShader(void** /* customData */) const { return false; }
 #endif
 
     //////////////////////////////////////////////////////////////////////////