diff --git a/lib/krb5/data.c b/lib/krb5/data.c
index c32d9be88..d8db01569 100644
--- a/lib/krb5/data.c
+++ b/lib/krb5/data.c
@@ -59,7 +59,7 @@ krb5_error_code
 krb5_data_alloc(krb5_data *p, int len)
 {
     p->data = malloc(len);
-    if(p->data == NULL)
+    if(len && p->data == NULL)
 	return ENOMEM;
     p->length = len;
     return 0;
@@ -70,7 +70,7 @@ krb5_data_realloc(krb5_data *p, int len)
 {
     void *tmp;
     tmp = realloc(p->data, len);
-    if(!tmp)
+    if(len && !tmp)
 	return ENOMEM;
     p->data = tmp;
     p->length = len;