diff --git a/libavformat/udp.c b/libavformat/udp.c
index b9aa7491a6..bd7665ef74 100644
--- a/libavformat/udp.c
+++ b/libavformat/udp.c
@@ -41,6 +41,10 @@
 #include <pthread.h>
 #endif
 
+#ifndef HAVE_PTHREAD_CANCEL
+#define HAVE_PTHREAD_CANCEL 0
+#endif
+
 #ifndef IPV6_ADD_MEMBERSHIP
 #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
 #define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP