diff --git a/lib/krb5/crypto.c b/lib/krb5/crypto.c
index cf19d6452..65358d14f 100644
--- a/lib/krb5/crypto.c
+++ b/lib/krb5/crypto.c
@@ -3414,7 +3414,7 @@ decrypt_internal_derived(krb5_context context,
     l = len - et->confoundersize;
     memmove(p, p + et->confoundersize, l);
     result->data = realloc(p, l);
-    if(result->data == NULL) {
+    if(result->data == NULL && l != 0) {
 	free(p);
 	krb5_set_error_string(context, "malloc: out of memory");
 	return ENOMEM;
@@ -3479,7 +3479,7 @@ decrypt_internal(krb5_context context,
     l = len - et->confoundersize - checksum_sz;
     memmove(p, p + et->confoundersize + checksum_sz, l);
     result->data = realloc(p, l);
-    if(result->data == NULL) {
+    if(result->data == NULL && l != 0) {
 	free(p);
 	krb5_set_error_string(context, "malloc: out of memory");
 	return ENOMEM;
@@ -3523,7 +3523,7 @@ decrypt_internal_special(krb5_context context,
 
     memmove (p, p + cksum_sz + et->confoundersize, sz);
     result->data = realloc(p, sz);
-    if(result->data == NULL) {
+    if(result->data == NULL && sz != 0) {
 	free(p);
 	krb5_set_error_string(context, "malloc: out of memory");
 	return ENOMEM;