1 files changed, 7 insertions, 0 deletions
diff --git a/missing/flock.c b/missing/flock.c
index c0b3f80601..9daf1c38cc 100644
--- a/missing/flock.c
+++ b/missing/flock.c
@@ -2,6 +2,13 @@
 #include "ruby/ruby.h"
 
 #if defined _WIN32
+#elif defined __wasi__
+#include <errno.h>
+
+int flock(int fd, int operation) {
+  errno = EINVAL;
+  return -1;
+}
 #elif defined HAVE_FCNTL && defined HAVE_FCNTL_H
 
 /* These are the flock() constants.  Since this systems doesn't have