diff --git a/programs/develop/libraries/libs-dev/libimg/png/png.asm b/programs/develop/libraries/libs-dev/libimg/png/png.asm
index 3f04d5c6d6..f609cb8a16 100644
--- a/programs/develop/libraries/libs-dev/libimg/png/png.asm
+++ b/programs/develop/libraries/libs-dev/libimg/png/png.asm
@@ -280,7 +280,8 @@ end virtual
 	lodsd
 	dec	esi
 	bswap	eax
-	shr	eax, 8
+	mov     al, 0xff
+	ror	eax, 8
 	stosd
 	jmp	@b
 @@:
@@ -1142,4 +1143,4 @@ endl
 	xor	eax,eax
 .quit:
 	ret
-endp
\ No newline at end of file
+endp