diff --git a/util/cpp/preprocess.c b/util/cpp/preprocess.c
index d33d17ac8..0fb437862 100644
--- a/util/cpp/preprocess.c
+++ b/util/cpp/preprocess.c
@@ -92,7 +92,7 @@ preprocess(fn)
 					}
 					for (;;) {
 						LoadChar(c);
-						if (class(c) == STNL) {
+						if (c == '\n') {
 							++LineNumber;
 							++lineno;
 							echo(c);