diff --git a/src/gpre/gpre.cpp b/src/gpre/gpre.cpp
index cc69dc91c8..06b24a9f62 100644
--- a/src/gpre/gpre.cpp
+++ b/src/gpre/gpre.cpp
@@ -844,6 +844,7 @@ int main(int argc, char* argv[])
 		}
 
 		if (renamed) {
+			// Warning: modifying program's args.
 			TEXT* p;
 			for (p = out_file_name; *p; p++);
 #ifdef VMS
diff --git a/src/gpre/gpre.h b/src/gpre/gpre.h
index 708e0aa6fb..8f50161e0f 100644
--- a/src/gpre/gpre.h
+++ b/src/gpre/gpre.h
@@ -1490,7 +1490,7 @@ struct GpreGlobals{
 	TEXT ada_package[256];
 	const TEXT* ada_null_address;
 	DBB isc_databases;
-	TEXT* default_user;
+	const TEXT* default_user;
 	TEXT* default_password;
 	const TEXT* default_lc_ctype;
 	gpre_req* requests;