diff --git a/lib/gssapi/krb5/unwrap.c b/lib/gssapi/krb5/unwrap.c
index 943ad6219..485b088a9 100644
--- a/lib/gssapi/krb5/unwrap.c
+++ b/lib/gssapi/krb5/unwrap.c
@@ -105,7 +105,7 @@ OM_uint32 gss_unwrap
 
   /* check pad */
 
-  pad = (char *)input_message_buffer->value + input_message_buffer->length - 1;
+  pad = (u_char *)input_message_buffer->value + input_message_buffer->length - 1;
   padlength = *pad;
 
   for (i = padlength; i >= 0 && *pad == padlength; i--, pad--)
diff --git a/lib/gssapi/unwrap.c b/lib/gssapi/unwrap.c
index 943ad6219..485b088a9 100644
--- a/lib/gssapi/unwrap.c
+++ b/lib/gssapi/unwrap.c
@@ -105,7 +105,7 @@ OM_uint32 gss_unwrap
 
   /* check pad */
 
-  pad = (char *)input_message_buffer->value + input_message_buffer->length - 1;
+  pad = (u_char *)input_message_buffer->value + input_message_buffer->length - 1;
   padlength = *pad;
 
   for (i = padlength; i >= 0 && *pad == padlength; i--, pad--)