diff --git a/src/r_main.c b/src/r_main.c
index 281058362d020def4eb217005aaf2f68771bd1ac..bfca180d0011ed9dc34d68bf9948b448b12827b8 100644
--- a/src/r_main.c
+++ b/src/r_main.c
@@ -118,7 +118,7 @@ lighttable_t *scalelightfixed[MAXLIGHTSCALE];
 lighttable_t *zlight[LIGHTLEVELS][MAXLIGHTZ];
 
 // Hack to support extra boom colormaps.
-extracolormap_t *extra_colormaps;
+extracolormap_t *extra_colormaps = NULL;
 
 static CV_PossibleValue_t drawdist_cons_t[] = {
 	{256, "256"},	{512, "512"},	{768, "768"},