diff --git a/analysis/spikes/correlation/CCGHeart.c b/analysis/spikes/correlation/CCGHeart.c
index f959e24b..016709cd 100755
--- a/analysis/spikes/correlation/CCGHeart.c
+++ b/analysis/spikes/correlation/CCGHeart.c
@@ -22,7 +22,7 @@
    If you think this program is anal, you're right.  Use the MATLAB wrapper instead.
  */
 
-
+#include <string.h>
 #include "mex.h"
 #include "matrix.h"
 #include <stdlib.h>