Added include for assert
diff --git a/src/FTGLTextureFont.cpp b/src/FTGLTextureFont.cpp
index 16dd58f..3b8836e 100755
--- a/src/FTGLTextureFont.cpp
+++ b/src/FTGLTextureFont.cpp
@@ -1,3 +1,4 @@
+#include <cassert>
#include <string> // For memset
#include "FTGLTextureFont.h"