diff --git a/compat.h b/compat.h
index bf6e5360..2e433a09 100644
--- a/compat.h
+++ b/compat.h
@@ -176,6 +176,13 @@ typedef uint64_t u_int64_t;
 #define TTY_NAME_MAX 32
 #endif
 
+#ifndef HAVE_FLOCK
+#define LOCK_SH 0
+#define LOCK_EX 0
+#define LOCK_NB 0
+#define flock(fd, op) (0)
+#endif
+
 #ifndef HAVE_BZERO
 #undef bzero
 #define bzero(buf, len) memset(buf, 0, len);
diff --git a/configure.ac b/configure.ac
index b524ff8e..fc71f02a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -386,6 +386,7 @@ AC_CHECK_FUNCS(
 	[ \
 		bzero \
 		dirfd \
+		flock \
 		setproctitle \
 		sysconf \
 		cfmakeraw \