diff --git a/compat/mingw.h b/compat/mingw.h
index a1808b4e6b..69bb43dc35 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -142,6 +142,7 @@ static inline int fcntl(int fd, int cmd, ...)
 #define sigemptyset(x) (void)0
 static inline int sigaddset(sigset_t *set, int signum)
 { return 0; }
+#define SIG_BLOCK 0
 #define SIG_UNBLOCK 0
 static inline int sigprocmask(int how, const sigset_t *set, sigset_t *oldset)
 { return 0; }
diff --git a/compat/win32/pthread.h b/compat/win32/pthread.h
index b6ed9e7462..1c164088fb 100644
--- a/compat/win32/pthread.h
+++ b/compat/win32/pthread.h
@@ -104,4 +104,11 @@ static inline void *pthread_getspecific(pthread_key_t key)
 	return TlsGetValue(key);
 }
 
+#ifndef __MINGW64_VERSION_MAJOR
+static inline int pthread_sigmask(int how, const sigset_t *set, sigset_t *oset)
+{
+	return 0;
+}
+#endif
+
 #endif /* PTHREAD_H */