diff --git a/MobileGL/MG_Util/Metrics/BufferMetrics.cpp b/MobileGL/MG_Util/Metrics/BufferMetrics.cpp
index bcb2e0ad..bd2b084e 100644
--- a/MobileGL/MG_Util/Metrics/BufferMetrics.cpp
+++ b/MobileGL/MG_Util/Metrics/BufferMetrics.cpp
@@ -114,6 +114,7 @@ namespace MobileGL {
                 return 4 * 3 * sizeof(GLdouble);
 
             default:
+                MOBILEGL_ASSERT(false, "Unknown GL Type!");
                 return -1;
             }
         }