1 files changed, 2 insertions, 0 deletions
diff --git a/sync.c b/sync.c
index 87d5a30..b2b8323 100644
--- a/sync.c
+++ b/sync.c
@@ -6,6 +6,8 @@
  * synchronisation.
  */
 
+#include <errno.h>
+
 /* POSIX STANDARD: A thread may pass a value pointer to some data via
    pthread_exit(). That pointer will be stored in a location supplied
    as an argument to pthread_join().