diff --git a/common/jpeg/jdct.h b/common/jpeg/jdct.h
index c834410..7b49a97 100644
--- a/common/jpeg/jdct.h
+++ b/common/jpeg/jdct.h
@@ -28,10 +28,16 @@
  */
 
 #if BITS_IN_JSAMPLE == 8
+#ifndef WITH_SIMD
 typedef int DCTELEM;		/* 16 or 32 bits is fine */
 typedef unsigned int UDCTELEM;
 typedef unsigned long long UDCTELEM2;
 #else
+typedef short DCTELEM;  /* prefer 16 bit with SIMD for parellelism */
+typedef unsigned short UDCTELEM;
+typedef unsigned int UDCTELEM2;
+#endif
+#else
 typedef INT32 DCTELEM;		/* must have 32 bits */
 typedef UINT32 UDCTELEM;
 typedef unsigned long long UDCTELEM2;