diff --git a/appl/gssmask/common.c b/appl/gssmask/common.c
index 1382997ee..af8a13343 100644
--- a/appl/gssmask/common.c
+++ b/appl/gssmask/common.c
@@ -55,7 +55,7 @@ add_list(char ****list, size_t *listlen, char **str, size_t len)
     size_t i;
     *list = erealloc(*list, sizeof(**list) * (*listlen + 1));
 
-    (*list)[*listlen] = ecalloc(len, sizeof(str[0]));
+    (*list)[*listlen] = ecalloc(len, sizeof(**list));
     for (i = 0; i < len; i++)
 	(*list)[*listlen][i] = str[i];
     (*listlen)++;