2 files changed, 14 insertions, 9 deletions

diff --git a/mjit.h b/mjit.h
index 1694fcba88..acb8b22e25 100644
--- a/mjit.h
+++ b/mjit.h
@@ -137,28 +137,35 @@ mjit_exec_slowpath(rb_execution_context_t *ec, const rb_iseq_t *iseq, struct rb_
 }
 
 // Try to execute the current iseq in ec.  Use JIT code if it is ready.
-// If it is not, add ISEQ to the compilation queue and return Qundef.
+// If it is not, add ISEQ to the compilation queue and return Qundef for MJIT.
+// YJIT compiles on the thread running the iseq.
 static inline VALUE
 mjit_exec(rb_execution_context_t *ec)
 {
     const rb_iseq_t *iseq = ec->cfp->iseq;
     struct rb_iseq_constant_body *body = iseq->body;
+    bool yjit_enabled = false;
+#ifndef MJIT_HEADER
+    // Don't want to compile with YJIT or use code generated by YJIT
+    // when running inside code generated by MJIT.
+    yjit_enabled = rb_yjit_enabled_p();
+#endif
 
-    if (mjit_call_p || rb_yjit_enabled_p()) {
+    if (mjit_call_p || yjit_enabled) {
         body->total_calls++;
     }
 
 #ifndef MJIT_HEADER
-    if (rb_yjit_enabled_p() && !mjit_call_p && body->total_calls == rb_yjit_call_threshold())  {
+    if (yjit_enabled && !mjit_call_p && body->total_calls == rb_yjit_call_threshold())  {
         // If we couldn't generate any code for this iseq, then return
         // Qundef so the interpreter will handle the call.
         if (!rb_yjit_compile_iseq(iseq, ec)) {
-          return Qundef;
+            return Qundef;
         }
     }
 #endif
 
-    if (!(mjit_call_p || rb_yjit_enabled_p()))
+    if (!(mjit_call_p || yjit_enabled))
         return Qundef;
 
     RB_DEBUG_COUNTER_INC(mjit_exec);
@@ -167,8 +174,8 @@ mjit_exec(rb_execution_context_t *ec)
 
     // YJIT tried compiling this function once before and couldn't do
     // it, so return Qundef so the interpreter handles it.
-    if (rb_yjit_enabled_p() && func == 0) {
-      return Qundef;
+    if (yjit_enabled && func == 0) {
+        return Qundef;
     }
 
     if (UNLIKELY((uintptr_t)func <= LAST_JIT_ISEQ_FUNC)) {
diff --git a/yjit.h b/yjit.h
index 1a1d590502..af0ebd0179 100644
--- a/yjit.h
+++ b/yjit.h
@@ -62,10 +62,8 @@ struct rb_yjit_options {
     bool test_backend;
 };
 
-MJIT_SYMBOL_EXPORT_BEGIN
 bool rb_yjit_enabled_p(void);
 unsigned rb_yjit_call_threshold(void);
-MJIT_SYMBOL_EXPORT_END
 
 void rb_yjit_invalidate_all_method_lookup_assumptions(void);
 void rb_yjit_method_lookup_change(VALUE klass, ID mid);