diff --git a/vm/compiler.c b/vm/compiler.c
index 2e58a43c5e..b8f3366499 100644
--- a/vm/compiler.c
+++ b/vm/compiler.c
@@ -137,7 +137,7 @@ void finalize_code_block(F_COMPILED *relocating, CELL code_start,
 	CELL scan;
 
 	if(relocating->finalized != false)
-		critical_error("Finalizing a finalized block",relocating);
+		critical_error("Finalizing a finalized block",(CELL)relocating);
 
 	for(scan = words_start; scan < words_end; scan += CELLS)
 		put(scan,untag_word(get(scan))->xt);