diff --git a/lib/ruby_vm/mjit/insn_compiler.rb b/lib/ruby_vm/mjit/insn_compiler.rb
index 756e04df4c..9562adc4c4 100644
--- a/lib/ruby_vm/mjit/insn_compiler.rb
+++ b/lib/ruby_vm/mjit/insn_compiler.rb
@@ -2318,7 +2318,6 @@ module RubyVM::MJIT
       iseq = def_iseq_ptr(cme.def)
       opt_pc = jit_callee_setup_arg(jit, ctx, asm, flags, argc, iseq)
       if opt_pc == CantCompile
-        # We hit some unsupported path of vm_callee_setup_arg
         return CantCompile
       end
 
@@ -2327,14 +2326,14 @@ module RubyVM::MJIT
         asm.incr_counter(:send_tailcall)
         return CantCompile
       end
-      jit_call_iseq_setup_normal(jit, ctx, asm, cme, flags, argc, iseq, block_handler, send_shift:)
+      jit_call_iseq_setup_normal(jit, ctx, asm, cme, flags, argc, iseq, block_handler, opt_pc, send_shift:)
     end
 
     # vm_call_iseq_setup_normal (vm_call_iseq_setup_2 -> vm_call_iseq_setup_normal)
     # @param jit [RubyVM::MJIT::JITState]
     # @param ctx [RubyVM::MJIT::Context]
     # @param asm [RubyVM::MJIT::Assembler]
-    def jit_call_iseq_setup_normal(jit, ctx, asm, cme, flags, argc, iseq, block_handler, send_shift:)
+    def jit_call_iseq_setup_normal(jit, ctx, asm, cme, flags, argc, iseq, block_handler, opt_pc, send_shift:)
       # We will not have side exits from here. Adjust the stack.
       if flags & C.VM_CALL_OPT_SEND != 0
         jit_call_opt_send_shift_stack(ctx, asm, argc, send_shift:)
@@ -2358,7 +2357,8 @@ module RubyVM::MJIT
 
       # Jump to a stub for the callee ISEQ
       callee_ctx = Context.new
-      stub_next_block(iseq, iseq.body.iseq_encoded.to_i, callee_ctx, asm)
+      pc = (iseq.body.iseq_encoded + opt_pc).to_i
+      stub_next_block(iseq, pc, callee_ctx, asm)
 
       EndBlock
     end
@@ -2621,6 +2621,12 @@ module RubyVM::MJIT
       asm.cmp(CFP, :rax)
       asm.jbe(counted_exit(side_exit(jit, ctx), :send_stackoverflow))
 
+      if iseq
+        # This was not handled in jit_callee_setup_arg
+        opts_filled = argc - iseq.body.param.lead_num # TODO: kwarg
+        opts_missing = iseq.body.param.opt_num - opts_filled
+        local_size += opts_missing
+      end
       local_size.times do |i|
         asm.comment('set local variables') if i == 0
         local_index = ctx.sp_offset + i
@@ -2720,9 +2726,29 @@ module RubyVM::MJIT
           end
 
           return 0
+        elsif C.rb_iseq_only_optparam_p(iseq)
+          if jit_caller_setup_arg(jit, ctx, asm, flags) == CantCompile
+            return CantCompile
+          end
+          if jit_caller_remove_empty_kw_splat(jit, ctx, asm, flags) == CantCompile
+            return CantCompile
+          end
+
+          lead_num = iseq.body.param.lead_num
+          opt_num = iseq.body.param.opt_num
+          opt = argc - lead_num
+
+          if opt < 0 || opt > opt_num
+            asm.incr_counter(:send_arity)
+            return CantCompile
+          end
+
+          # Qnil push is handled in jit_push_frame
+
+          return iseq.body.param.opt_table[opt]
         else
           # We don't support the remaining `else if`s yet.
-          asm.incr_counter(:send_iseq_not_simple)
+          asm.incr_counter(:send_iseq_not_only_optparam)
           return CantCompile
         end
       end
diff --git a/mjit_c.h b/mjit_c.h
index 5121cd67a1..261af15f1e 100644
--- a/mjit_c.h
+++ b/mjit_c.h
@@ -137,7 +137,7 @@ MJIT_RUNTIME_COUNTERS(
     send_block_handler,
     send_block_setup,
 
-    send_iseq_not_simple,
+    send_iseq_not_only_optparam,
     send_iseq_kw_splat,
 
     send_cfunc_variadic,
diff --git a/mjit_c.rb b/mjit_c.rb
index 3570d9bb8d..c67208ded1 100644
--- a/mjit_c.rb
+++ b/mjit_c.rb
@@ -246,6 +246,14 @@ module RubyVM::MJIT # :nodoc: all
       Primitive.cexpr! 'UINT2NUM(imemo_type((VALUE)NUM2SIZET(_ptr)))'
     end
 
+    def rb_iseq_only_optparam_p(iseq)
+      _iseq = iseq.to_i
+      Primitive.cstmt! %{
+        extern bool rb_iseq_only_optparam_p(const rb_iseq_t *iseq);
+        return RBOOL(rb_iseq_only_optparam_p((rb_iseq_t *)NUM2SIZET(_iseq)));
+      }
+    end
+
     #========================================================================================
     #
     # Old stuff
@@ -1265,7 +1273,7 @@ module RubyVM::MJIT # :nodoc: all
       send_blockiseq: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_blockiseq)")],
       send_block_handler: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_block_handler)")],
       send_block_setup: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_block_setup)")],
-      send_iseq_not_simple: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_iseq_not_simple)")],
+      send_iseq_not_only_optparam: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_iseq_not_only_optparam)")],
       send_iseq_kw_splat: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_iseq_kw_splat)")],
       send_cfunc_variadic: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_cfunc_variadic)")],
       send_cfunc_too_many_args: [CType::Immediate.parse("size_t"), Primitive.cexpr!("OFFSETOF((*((struct rb_mjit_runtime_counters *)NULL)), send_cfunc_too_many_args)")],