diff --git a/vlib/os/os.v b/vlib/os/os.v
index 1a445ac97a..42733d9e99 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -683,7 +683,7 @@ pub fn get_raw_line() string {
 	} $else {
 		max := size_t(0)
 		mut buf := charptr(0)
-		nr_chars := C.getline(&buf, &max, stdin)
+		nr_chars := C.getline(&buf, &max, C.stdin)
 		//defer { unsafe{ free(buf) } }
 		if nr_chars == 0 || nr_chars == -1 {
 			return ''
@@ -1118,7 +1118,7 @@ pub fn flush_stdout() {
 }
 
 pub fn flush() {
-	C.fflush(stdout)
+	C.fflush(C.stdout)
 }
 
 pub fn mkdir_all(path string) {
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 4a309716e6..9eba420f1e 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -944,11 +944,13 @@ pub fn (c mut Checker) ident(ident mut ast.Ident) table.Type {
 			return fn_type
 		}
 	}
-	// TODO
-	// c.error('unknown ident: `$ident.name`', ident.pos)
 	if ident.is_c {
 		return table.int_type
 	}
+	// TODO
+	if ident.name != '_' {
+		c.error('unknown ident: `$ident.name`', ident.pos)
+	}
 	return table.void_type
 }