diff --git a/stim/visualization/colormap.h b/stim/visualization/colormap.h
index b0807f3..a0a39b8 100644
--- a/stim/visualization/colormap.h
+++ b/stim/visualization/colormap.h
@@ -1,5 +1,6 @@
 #ifndef STIM_COLORMAP_H
 #define STIM_COLORMAP_H
+#define USING_OPENCV
 
 #include <string>
 #include <stdlib.h>
--
libgit2 0.21.4