diff --git a/src/racket/src/error.c b/src/racket/src/error.c
index 5eb7919113..e9ba62f123 100644
--- a/src/racket/src/error.c
+++ b/src/racket/src/error.c
@@ -464,7 +464,7 @@ static intptr_t sch_vsprintf(char *s, intptr_t maxlen, const char *msg, va_list
 	  {
 	    int en, he, none = 0;
 	    char *es;
-            Scheme_Object *err_kind;
+            Scheme_Object *err_kind = NULL;
             
 	    if (type == 'm') {
               none = !ints[ip++];