diff --git a/src/fgetln.c b/src/fgetln.c
index 5f646e4..4d1726e 100644
--- a/src/fgetln.c
+++ b/src/fgetln.c
@@ -50,6 +50,8 @@ fgetln(FILE *stream, size_t *len)
 	struct filebuf *fb;
 	ssize_t nread;
 
+	flockfile(stream);
+
 	/* Try to diminish the possibility of several fgetln() calls being
 	 * used on different streams, by using a pool of buffers per file. */
 	fb = &fb_pool[fb_pool_cur];
@@ -61,6 +63,9 @@ fgetln(FILE *stream, size_t *len)
 	fb->fp = stream;
 
 	nread = getline(&fb->buf, &fb->len, stream);
+
+	funlockfile(stream);
+
 	/* Note: the getdelim/getline API ensures nread != 0. */
 	if (nread == -1) {
 		*len = 0;
diff --git a/src/fparseln.c b/src/fparseln.c
index 959df11..effb849 100644
--- a/src/fparseln.c
+++ b/src/fparseln.c
@@ -35,8 +35,6 @@ __RCSID("$NetBSD: fparseln.c,v 1.10 2009/10/21 01:07:45 snj Exp $");
 #include <string.h>
 #include <stdlib.h>
 
-#define FLOCKFILE(fp)
-#define FUNLOCKFILE(fp)
 #define _DIAGASSERT(t)
 
 static int isescaped(const char *, const char *, int);
@@ -104,7 +102,7 @@ fparseln(FILE *fp, size_t *size, size_t *lineno, const char str[3], int flags)
 	 */
 	nl  = '\n';
 
-	FLOCKFILE(fp);
+	flockfile(fp);
 
 	while (cnt) {
 		cnt = 0;
@@ -151,7 +149,7 @@ fparseln(FILE *fp, size_t *size, size_t *lineno, const char str[3], int flags)
 		}
 
 		if ((cp = realloc(buf, len + s + 1)) == NULL) {
-			FUNLOCKFILE(fp);
+			funlockfile(fp);
 			free(buf);
 			free(ptr);
 			return NULL;
@@ -163,7 +161,7 @@ fparseln(FILE *fp, size_t *size, size_t *lineno, const char str[3], int flags)
 		buf[len] = '\0';
 	}
 
-	FUNLOCKFILE(fp);
+	funlockfile(fp);
 	free(ptr);
 
 	if ((flags & FPARSELN_UNESCALL) != 0 && esc && buf != NULL &&