diff --git a/testcases/bball/tga_reader.h b/testcases/bball/tga_reader.h
index 0d500fe18645af8306638be02e2bd82c5bb590fa..a1d50dfc1f2357f046ebd74d94a1c4e8059856c4 100755
--- a/testcases/bball/tga_reader.h
+++ b/testcases/bball/tga_reader.h
@@ -30,8 +30,8 @@ typedef struct _TGA_ORDER {
 	int alphaShift;
 } TGA_ORDER;
 
-const TGA_ORDER *TGA_READER_ARGB;
-const TGA_ORDER *TGA_READER_ABGR;
+extern const TGA_ORDER *TGA_READER_ARGB;
+extern const TGA_ORDER *TGA_READER_ABGR;
 
 void *tgaMalloc(size_t size);
 void tgaFree(void *memory);