diff --git a/native_exec/simple_x86.py b/native_exec/simple_x86.py
index 4fad52e..fd303eb 100644
--- a/native_exec/simple_x86.py
+++ b/native_exec/simple_x86.py
@@ -547,7 +547,8 @@ class Dec(Instruction):
     encoding = [(RawBits.from_int(5, 0x48 >> 3), X86RegisterSelector())]
 
 class Inc(Instruction):
-    encoding = [(RawBits.from_int(5, 0x40 >> 3), X86RegisterSelector())]
+    encoding = [(RawBits.from_int(5, 0x40 >> 3), X86RegisterSelector()),
+                (RawBits.from_int(8, 0xff), Slash(0)),]
 
 class Add(Instruction):
     encoding = [(RawBits.from_int(8, 0x05), RegisterEax(), Imm32()),
diff --git a/native_exec/test_simple_x86.py b/native_exec/test_simple_x86.py
index 1d72af4..4006cae 100644
--- a/native_exec/test_simple_x86.py
+++ b/native_exec/test_simple_x86.py
@@ -95,6 +95,9 @@ TestInstr(Mov)('AX', mem('fs:[EAX + ECX * 4+0x30]'))
 TestInstr(Add)('EAX', 8)
 TestInstr(Add)('EAX', 0xffffffff)
 
+TestInstr(Inc)('EAX')
+TestInstr(Inc)(mem('[0x42424242]'))
+
 TestInstr(Lea)('EAX', mem('[EAX + 1]'))
 TestInstr(Lea)('ECX', mem('[EDI + -0xff]'))