diff --git a/src/tail.c b/src/tail.c
index 4a74e2a..d576dfa 100644
--- a/src/tail.c
+++ b/src/tail.c
@@ -121,7 +121,7 @@ int main(int argc, char *argv[]) {
 
 	FILE *file;
 
-	if (optind = argc) {
+	if (optind == argc) {
 		fn(stdin, num);
 
 		if (f) { tailf(stdin); }