diff --git a/configure.ac b/configure.ac
index 25ede780..7e689187 100644
--- a/configure.ac
+++ b/configure.ac
@@ -371,7 +371,7 @@ dnl Checks for functions and headers
 AC_CHECK_FUNC(clock_gettime, , [AC_CHECK_LIB(rt, clock_gettime)])
 AC_CHECK_FUNC(fegetenv, , [AC_CHECK_LIB(m, fegetenv)])
 
-AC_CHECK_FUNCS([SecureZeroMemory arc4random])
+AC_CHECK_FUNCS([SecureZeroMemory arc4random arc4random_buf])
 
 AC_SUBST([LIBTOOL_EXTRA_FLAGS])
 
diff --git a/src/libsodium/sodium/utils.c b/src/libsodium/sodium/utils.c
index 7026b497..6263dfc1 100644
--- a/src/libsodium/sodium/utils.c
+++ b/src/libsodium/sodium/utils.c
@@ -54,7 +54,7 @@ _sodium_alignedcalloc(unsigned char ** const unaligned_p, const size_t len)
         return NULL;
     }
     *unaligned_p = unaligned;
-#ifdef HAVE_ARC4RANDOM
+#ifdef HAVE_ARC4RANDOM_BUF
     (void) i;
     arc4random_buf(unaligned, len + (size_t) 256U);
 #else