diff --git a/LR35902/LR35902.cs b/LR35902/LR35902.cs
index 6628d44..a0efed9 100644
--- a/LR35902/LR35902.cs
+++ b/LR35902/LR35902.cs
@@ -56,7 +56,7 @@ namespace LR35902
 
         private bool Stopped { get; set; }
 
-        private bool _deferredInterruptEnable;
+        public bool EI { get; set; }
 
         #region MWR pin
 
@@ -196,10 +196,10 @@ namespace LR35902
         {
             this.prefixCB = false;
 
-            if ( this._deferredInterruptEnable)
+            if (this.EI)
             {
                 this.EnableInterrupts();
-                this._deferredInterruptEnable = false;
+                this.EI = false;
             }
 
             if (this.MaskedInterrupts != 0)
@@ -235,7 +235,7 @@ namespace LR35902
             this.RaiseWR();
             this.RaiseRD();
             this.RaiseMWR();
-            this._deferredInterruptEnable = false;
+            this.EI = false;
         }
 
         protected override void HandleRESET()
@@ -839,7 +839,7 @@ namespace LR35902
                                     this.DisableInterrupts();
                                     break;
                                 case 7: // EI
-                                    this._deferredInterruptEnable = true;
+                                    this.EI = true;
                                     break;
                                 default:
                                     break;
diff --git a/LR35902/SM83.HarteTest/Checker.cs b/LR35902/SM83.HarteTest/Checker.cs
index b9bb397..bf98b29 100644
--- a/LR35902/SM83.HarteTest/Checker.cs
+++ b/LR35902/SM83.HarteTest/Checker.cs
@@ -219,6 +219,12 @@
                 ie_good = this.Check("IE", final.IE.Value, cpu.IE);
             }
 
+            var ei_good = true;
+            if (final.EI is not null)
+            {
+                ei_good = this.Check("EI", final.EI.Value, (byte)(cpu.EI ? 1 : 0));
+            }
+
             if (!f_good)
             {
                 this.Messages.Add($"Expected flags: {LR35902.Disassembler.AsFlags(final.F)}");
@@ -255,7 +261,7 @@
                 && d_good && e_good
                 && h_good && l_good
                 && ime_good
-                && ie_good;
+                && ie_good && ei_good;
         }
 
         private void Raise(string what, ushort expected, ushort actual) => this.Messages.Add($"{what}: expected: {expected:X4}, actual: {actual:X4}");