diff --git a/ChangeLog b/ChangeLog
index 950a19645501bd74941e64dc3e6c5230d6d68458..2208874c876662477986e84591aa9ef22ea00b55 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2016-03-15  Niels Möller  <nisse@lysator.liu.se>
 
+	* blowfish.c (blowfish_encrypt, blowfish_decrypt): Use READ_UINT32
+	macro. Fixes an undefined shift, reported by Nikos
+	Mavrogiannopoulos.
+
 	From Nikos Mavrogiannopoulos.
 	* configure.ac (HOGWEED_EXTRA_SYMBOLS): Add "mp_*", when building
 	with mini-gmp.
diff --git a/blowfish.c b/blowfish.c
index ba921e71bce0dea2e9831813c2153d70e5da983d..52040f13f2b01a67875ad61a905bfb4908f83fda 100644
--- a/blowfish.c
+++ b/blowfish.c
@@ -337,8 +337,8 @@ blowfish_encrypt (const struct blowfish_ctx *ctx,
     {
       uint32_t d1, d2;
 
-      d1 = src[0] << 24 | src[1] << 16 | src[2] << 8 | src[3];
-      d2 = src[4] << 24 | src[5] << 16 | src[6] << 8 | src[7];
+      d1 = READ_UINT32(src);
+      d2 = READ_UINT32(src+4);
       encrypt (ctx, &d1, &d2);
       dst[0] = (d1 >> 24) & 0xff;
       dst[1] = (d1 >> 16) & 0xff;
@@ -359,8 +359,8 @@ blowfish_decrypt (const struct blowfish_ctx *ctx,
     {
       uint32_t d1, d2;
 
-      d1 = src[0] << 24 | src[1] << 16 | src[2] << 8 | src[3];
-      d2 = src[4] << 24 | src[5] << 16 | src[6] << 8 | src[7];
+      d1 = READ_UINT32(src);
+      d2 = READ_UINT32(src+4);
       decrypt (ctx, &d1, &d2);
       dst[0] = (d1 >> 24) & 0xff;
       dst[1] = (d1 >> 16) & 0xff;