diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index 65da87fce907ad2bc7b52adba4651dc2c32786be..5ca2df790d3cfa5f4253a33a303219aaa8fc4394 100644
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/preprocess.c
@@ -156,7 +156,7 @@ static char *do_shell(int argc, char *argv[])
 		nread--;
 
 	/* remove trailing new lines */
-	while (buf[nread - 1] == '\n')
+	while (nread > 0 && buf[nread - 1] == '\n')
 		nread--;
 
 	buf[nread] = 0;