diff --git a/if1632/relay.c b/if1632/relay.c
index f66c5c145b5..13c7dc23748 100644
--- a/if1632/relay.c
+++ b/if1632/relay.c
@@ -274,7 +274,7 @@ void RELAY_Unimplemented16(void)
     char name[80];
     STACK16FRAME *frame = CURRENT_STACK16;
     BUILTIN_GetEntryPoint16( frame, name, &ordinal );
-    MESSAGE("No handler for Win16 routine %s (called from %04x:%04x)\n",
+    MESSAGE("FATAL: No handler for Win16 routine %s (called from %04x:%04x)\n",
             name, frame->cs, frame->ip );
     ExitProcess(1);
 }
diff --git a/relay32/builtin32.c b/relay32/builtin32.c
index b43771139e9..954acf23af3 100644
--- a/relay32/builtin32.c
+++ b/relay32/builtin32.c
@@ -425,7 +425,7 @@ void BUILTIN32_Unimplemented( const char *dllname, const char *funcname )
 {
     __RESTORE_ES;  /* Just in case */
 
-    MESSAGE( "No handler for Win32 routine %s.%s", dllname, funcname );
+    MESSAGE( "FATAL: No handler for Win32 routine %s.%s", dllname, funcname );
 #ifdef __GNUC__
     MESSAGE( " (called from %p)", __builtin_return_address(1) );
 #endif