diff --git a/misc/another_test.asm b/misc/another_test.asm
index 1ab8ad0..cac3c57 100644
--- a/misc/another_test.asm
+++ b/misc/another_test.asm
@@ -28,7 +28,7 @@ _end:
 ; Returns: R2 - Contains the length of the string
 strlen:
     copy r2, 0 ; length
-    copy byte r4, [r1]
+    copy byte r3, [r1]
     cmp r3, 0
     jz end ;The string is zero length
 loop:
diff --git a/src/parser.c b/src/parser.c
index ae104f2..c1bcb0a 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -167,7 +167,7 @@ void HandleOpcode(void) {
                         opcode->Value.Mnemonic = isByte ? COPYAB : COPYA;
                         opcode->Lemexe = isByte ? "copyab" : "copya";
 
-                        AdvanceParser();
+                        ExpectIdentifier(0, ForwardParser);
                     }
                     else {
                         ExpectPuncuation(LBracket, ForwardParser);
@@ -208,12 +208,18 @@ void HandleOpcode(void) {
 
                 TokenClass class = PeekToken()->Class;
 
-                if (class == NumberClass || class & IdentifierClass) {
+                if (class == NumberClass) {
                     opcode->Value.Mnemonic = CMPI;
                     opcode->Lemexe = "CMPI";
 
                     AdvanceParser();
                 }
+                else if (class & IdentifierClass) {
+                    opcode->Value.Mnemonic = CMPI;
+                    opcode->Lemexe = "CMPI";
+
+                    ExpectIdentifier(0, ForwardParser);
+                }
                 else {
                     ExpectRegister();
                 }