diff --git a/cpu/decoder.cpp b/cpu/decoder.cpp
index 9e0d257..f0f2a50 100644
--- a/cpu/decoder.cpp
+++ b/cpu/decoder.cpp
@@ -298,21 +298,9 @@ void Cpu::step()
           mcycles = 2;
         }
     }
-  else if(op & 0xC7 == 0xC7)
+  else if(op & 0xC7 == 0xC7) // RST
     {
-      u16 rst_addr;
-      switch((op >> 3) & 0x7)
-        {
-        case 0x0: rst_addr = 0x00; break;
-        case 0x1: rst_addr = 0x08; break;
-        case 0x2: rst_addr = 0x10; break;
-        case 0x3: rst_addr = 0x18; break;
-        case 0x4: rst_addr = 0x20; break;
-        case 0x5: rst_addr = 0x28; break;
-        case 0x6: rst_addr = 0x30; break;
-        case 0x7: rst_addr = 0x38; break;
-        }
-
+      u16 rst_addr = op & 0x38;
       doCall(rst_addr);
     }
   else