diff --git a/lang/cem/cpp.ansi/replace.c b/lang/cem/cpp.ansi/replace.c
index 5b2719c9a..781ef2069 100644
--- a/lang/cem/cpp.ansi/replace.c
+++ b/lang/cem/cpp.ansi/replace.c
@@ -195,6 +195,7 @@ expand_defined(repl)
 	if (parens && ch != ')') error(") missing");
 	if (!parens || ch != ')') UnGetChar();
 	add2repl(repl, (id && id->id_macro) ? '1' : '0');
+	add2repl(repl, ' ');
 }
 
 newarg(args)