diff --git a/tests/benchmarks/graphics.cpp b/tests/benchmarks/graphics.cpp
index fd4a471808..cfcfe2a4bf 100644
--- a/tests/benchmarks/graphics.cpp
+++ b/tests/benchmarks/graphics.cpp
@@ -103,6 +103,7 @@ public:
 
 #if wxUSE_GLCANVAS
         m_glCanvas = NULL;
+        m_glContext = NULL;
 
         if ( opts.useGL )
         {