diff --git a/mjit.h b/mjit.h
index 44cb6571b7..bdc186f788 100644
--- a/mjit.h
+++ b/mjit.h
@@ -125,13 +125,15 @@ mjit_exec(rb_execution_context_t *ec)
     total_calls = ++body->total_calls;
 
     func = body->jit_func;
-    if (UNLIKELY((uintptr_t)func <= (uintptr_t)LAST_JIT_ISEQ_FUNC)) {
+    uintptr_t func_i = (uintptr_t)func;
+    if (UNLIKELY(func_i <= LAST_JIT_ISEQ_FUNC)) {
 #     ifdef MJIT_HEADER
         RB_DEBUG_COUNTER_INC(mjit_frame_JT2VM);
 #     else
         RB_DEBUG_COUNTER_INC(mjit_frame_VM2VM);
 #     endif
-        switch ((enum rb_mjit_iseq_func)func) {
+        ASSUME(func_i <= LAST_JIT_ISEQ_FUNC);
+        switch ((enum rb_mjit_iseq_func)func_i) {
           case NOT_ADDED_JIT_ISEQ_FUNC:
             RB_DEBUG_COUNTER_INC(mjit_exec_not_added);
             if (total_calls == mjit_opts.min_calls && mjit_target_iseq_p(body)) {
diff --git a/vm_method.c b/vm_method.c
index 900096629d..7b29b2c20c 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -288,7 +288,7 @@ rb_method_definition_set(const rb_method_entry_t *me, rb_method_definition_t *de
 	    setup_method_cfunc_struct(UNALIGNED_MEMBER_PTR(def, body.cfunc), rb_f_notimplement, -1);
 	    return;
 	  case VM_METHOD_TYPE_OPTIMIZED:
-	    def->body.optimize_type = (enum method_optimized_type)opts;
+            def->body.optimize_type = (enum method_optimized_type)(intptr_t)opts;
 	    return;
 	  case VM_METHOD_TYPE_REFINED:
 	    {