diff --git a/src/convert.asm b/src/convert.asm
index ea08c7c..306851e 100644
--- a/src/convert.asm
+++ b/src/convert.asm
@@ -109,6 +109,7 @@ udec2str:
 ;	rcx*	Counts length of created string
 ;	r8*	Dividor for div
 ;	r9*	Store arg rsi (uppercase)
+;	r11*	Amount to add to number (for ASCII conversion, lowercase or uppercase)
 hex2str:
 	mov	r9, rsi
 	mov	rsi, cnvtBuff
@@ -122,19 +123,20 @@ hex2str:
 	.notZero:
 	mov	rax, rdi
 	xor	rcx, rcx
+
+	mov	r8, 87
+	test	r9, r9
+	cmovz	r11, r8
+	test	r9, r9
+	jz	.convert
+	mov	r11, 55
 	.convert:
 		xor	rdx, rdx
 		mov	r8, 16
 		div	r8
 		cmp	rdx, 10
 		jb	.num
-		test	r9, r9
-		jz	.lower
-		;.upper:
-		add	rdx, 55
-		jmp	.push
-		.lower:
-		add	rdx, 87
+		add	rdx, r11
 		jmp	.push
 		.num:
 		add	rdx, '0'