diff --git a/src/compiler/AST.c b/src/compiler/AST.c
index 8d3b9b1..97ca81e 100644
--- a/src/compiler/AST.c
+++ b/src/compiler/AST.c
@@ -20,18 +20,6 @@ str ArgumentType_toString(ArgumentType t){
     return _ArgumentType_str[t];
 }
 
-RegisterCode RegisterCode_parse(str r){
-    if(str_equals(r, STR("ax")))
-        return RegisterCode_ax;
-    if(str_equals(r, STR("bx")))
-        return RegisterCode_bx;
-    if(str_equals(r, STR("cx")))
-        return RegisterCode_cx;
-    if(str_equals(r, STR("dx")))
-        return RegisterCode_dx;
-    return RegisterCode_Unset;
-}
-
 
 void Section_init(Section* sec, str name){
     sec->name = name;
diff --git a/src/compiler/AST.h b/src/compiler/AST.h
index 769c4d7..8c2f878 100644
--- a/src/compiler/AST.h
+++ b/src/compiler/AST.h
@@ -2,6 +2,7 @@
 #include "../std.h"
 #include "../string/str.h"
 #include "../instructions/instructions.h"
+#include "../instructions/registers.h"
 #include "../collections/List.h"
 
 typedef enum ArgumentType {
@@ -15,16 +16,6 @@ typedef enum ArgumentType {
 
 str ArgumentType_toString(ArgumentType t);
 
-typedef enum RegisterCode {
-    RegisterCode_Unset,
-    RegisterCode_ax,
-    RegisterCode_bx,
-    RegisterCode_cx,
-    RegisterCode_dx
-} RegisterCode;
-
-RegisterCode RegisterCode_parse(str register_name);
-
 typedef struct Argument {
     ArgumentType type;
     union {
diff --git a/src/instructions/impl/MOV.c b/src/instructions/impl/MOV.c
index 567421b..fd20e1d 100644
--- a/src/instructions/impl/MOV.c
+++ b/src/instructions/impl/MOV.c
@@ -4,7 +4,7 @@
 i32 MOV_impl(VM* vm){
     u8 dst_register_i = 0;
     readRegisterVar(dst_register_i);
-    u8  src_register_i = 0;
+    u8 src_register_i = 0;
     readRegisterVar(src_register_i);
     if(dst_register_i == src_register_i){
         VM_setError(vm, "dst_register_i == src_register_i (%x) ", src_register_i);
diff --git a/src/instructions/impl/impl_macros.h b/src/instructions/impl/impl_macros.h
index 6dd7e1e..3a9e6b1 100644
--- a/src/instructions/impl/impl_macros.h
+++ b/src/instructions/impl/impl_macros.h
@@ -1,5 +1,6 @@
 #pragma once
 #include "../instructions.h"
+#include "../registers.h"
 
 #define readVar(VAR) {\
     if(!VM_dataRead(vm, &VAR, vm->current_pos, sizeof(VAR))) \
@@ -8,7 +9,7 @@
 }
 
 #define validateRegisterIndex(VAR) {\
-    if(VAR > sizeof(vm->registers)){\
+    if(VAR> sizeof(vm->registers)){\
         VM_setError(vm, "invalid register index (%x)", VAR);\
         return -1;\
     }\
@@ -16,6 +17,7 @@
 
 #define readRegisterVar(VAR) {\
     readVar(VAR);\
+    VAR -= 1;\
     validateRegisterIndex(VAR);\
 }
 
diff --git a/src/instructions/registers.c b/src/instructions/registers.c
new file mode 100644
index 0000000..70153e4
--- /dev/null
+++ b/src/instructions/registers.c
@@ -0,0 +1,13 @@
+#include "registers.h"
+
+RegisterCode RegisterCode_parse(str r){
+    if(str_equals(r, STR("ax")))
+        return RegisterCode_ax;
+    if(str_equals(r, STR("bx")))
+        return RegisterCode_bx;
+    if(str_equals(r, STR("cx")))
+        return RegisterCode_cx;
+    if(str_equals(r, STR("dx")))
+        return RegisterCode_dx;
+    return RegisterCode_Unset;
+}
diff --git a/src/instructions/registers.h b/src/instructions/registers.h
new file mode 100644
index 0000000..6b0db8e
--- /dev/null
+++ b/src/instructions/registers.h
@@ -0,0 +1,13 @@
+#pragma once
+#include "../std.h"
+#include "../string/str.h"
+
+typedef enum RegisterCode {
+    RegisterCode_Unset,
+    RegisterCode_ax,
+    RegisterCode_bx,
+    RegisterCode_cx,
+    RegisterCode_dx
+} RegisterCode;
+
+RegisterCode RegisterCode_parse(str register_name);