diff --git a/src/misc2.c b/src/misc2.c
index 86a1f9d..504cf0a 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -4712,7 +4712,8 @@
 	    {
 		wc_path = vim_strsave(search_ctx->ffsc_wc_path);
 		temp = alloc((int)(STRLEN(search_ctx->ffsc_wc_path)
-				 + (STRLEN(search_ctx->ffsc_fix_path)) - len));
+				 + STRLEN(search_ctx->ffsc_fix_path + len)
+				 + 1));
 	    }
 
 	    if (temp == NULL || wc_path == NULL)