diff --git a/ruby.c b/ruby.c
index 85ef9cbd80..0a130a3e02 100644
--- a/ruby.c
+++ b/ruby.c
@@ -1871,6 +1871,12 @@ process_options(int argc, char **argv, ruby_cmdline_options_t *opt)
          */
         rb_warning("-K is specified; it is for 1.8 compatibility and may cause odd behavior");
 
+#ifdef __OpenBSD__
+    /* Disable yjit on OpenBSD, stops --enable-all from failing with:
+       mmap call failed: Not supported */
+    opt->features.set &= ~FEATURE_BIT(yjit);
+#endif
+
 #if USE_MJIT
     if (opt->features.set & FEATURE_BIT(jit)) {
         opt->mjit.on = TRUE; /* set mjit.on for ruby_show_version() API and check to call mjit_init() */