diff --git a/libavcodec/atrac3.c b/libavcodec/atrac3.c
index 914998e7d9..78312258d4 100644
--- a/libavcodec/atrac3.c
+++ b/libavcodec/atrac3.c
@@ -179,8 +179,11 @@ static int decode_bytes(const uint8_t* inbuffer, uint8_t* out, int bytes){
     uint32_t* obuf = (uint32_t*) out;
 
     off = (intptr_t)inbuffer & 3;
-    buf = (const uint32_t*) (inbuffer - off);
-    c = av_be2ne32((0x537F6103 >> (off*8)) | (0x537F6103 << (32-(off*8))));
+    buf = (const uint32_t *)(inbuffer - off);
+    if (off)
+        c = av_be2ne32((0x537F6103U >> (off * 8)) | (0x537F6103U << (32 - (off * 8))));
+    else
+        c = av_be2ne32(0x537F6103U);
     bytes += 3 + off;
     for (i = 0; i < bytes/4; i++)
         obuf[i] = c ^ buf[i];