1 files changed, 9 insertions, 0 deletions
diff --git a/missing/flock.c b/missing/flock.c
index c0b3f80601..0b76961762 100644
--- a/missing/flock.c
+++ b/missing/flock.c
@@ -2,6 +2,15 @@
 #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