diff --git a/opengl/tools/glgen/stubs/jsr239/GLCHeader.cpp b/opengl/tools/glgen/stubs/jsr239/GLCHeader.cpp
index cc1033604..47430383d 100644
--- a/opengl/tools/glgen/stubs/jsr239/GLCHeader.cpp
+++ b/opengl/tools/glgen/stubs/jsr239/GLCHeader.cpp
@@ -182,7 +182,7 @@ getDirectBufferPointer(JNIEnv *_env, jobject buffer) {
             if (array) {
                 releasePointer(_env, array, buf, 0);
             }
-            buf = buf + offset;
+            buf = (char*)buf + offset;
         } else {
             jniThrowException(_env, "java/lang/IllegalArgumentException",
                               "Must use a native order direct Buffer");