diff --git a/src/Arch/i8051/i8051Disassembler.cs b/src/Arch/i8051/i8051Disassembler.cs
index b4c8d43364..e60e0c2746 100644
--- a/src/Arch/i8051/i8051Disassembler.cs
+++ b/src/Arch/i8051/i8051Disassembler.cs
@@ -18,18 +18,14 @@
  */
 #endregion
 
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using Reko.Core;
 using Reko.Core.Expressions;
 using Reko.Core.Machine;
 using Reko.Core.Memory;
 using Reko.Core.Services;
 using Reko.Core.Types;
+using System;
+using System.Collections.Generic;
 
 namespace Reko.Arch.i8051
 {
diff --git a/src/Arch/i8051/i8051Rewriter.cs b/src/Arch/i8051/i8051Rewriter.cs
index 7fd9021646..5861d78899 100644
--- a/src/Arch/i8051/i8051Rewriter.cs
+++ b/src/Arch/i8051/i8051Rewriter.cs
@@ -29,6 +29,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Diagnostics;
 
 namespace Reko.Arch.i8051
 {
@@ -459,7 +460,10 @@ private Expression OpSrc(MachineOperand op, RegisterStorage? dataMemory)
             case AddressOperand addr:
                 return addr.Address;
             case MemoryOperand mem:
-                var ea = EffectiveAddress(mem);
+                var (ea, alias) = EffectiveAddress(mem);
+                if (alias is not null)
+                    return alias;
+                Debug.Assert(ea is not null);
                 if (dataMemory != null)
                 {
                     return m.SegMem(mem.Width, binder.EnsureRegister(dataMemory), ea);
@@ -487,7 +491,7 @@ private Expression OpSrc(MachineOperand op, RegisterStorage? dataMemory)
             }
         }
 
-        private Expression EffectiveAddress(MemoryOperand mem)
+        private (Expression?, Expression?) EffectiveAddress(MemoryOperand mem)
         {
             Expression ea;
             if (mem.DirectAddress != null)
@@ -500,7 +504,7 @@ private Expression EffectiveAddress(MemoryOperand mem)
                 {
                     var alias = AliasedSpecialFunctionRegister(c.ToUInt16());
                     if (alias != null)
-                        return alias;
+                        return (null, alias);
                     ea = c;
                 }
                 else
@@ -537,7 +541,7 @@ private Expression EffectiveAddress(MemoryOperand mem)
             {
                 ea = m.Convert(ea, PrimitiveType.Byte, PrimitiveType.Word16);
             }
-            return ea;
+            return (ea, null);
         }
 
         /// <summary>