--- jcphuff.c
+++ jcphuff.c
@@ -14,6 +14,7 @@
  * suspension.
  */
 
+#include <stdint.h>
 #define JPEG_INTERNALS
 #include "jinclude.h"
 #include "jpeglib.h"
@@ -255,7 +256,7 @@
     if (c == 0xFF) {            /* need to stuff a zero byte? */
       emit_byte(entropy, 0);
     }
-    put_buffer <<= 8;
+    put_buffer = (uint_least32_t) put_buffer << 8;
     put_bits -= 8;
   }