diff --git a/contrib/install_db4.sh b/contrib/install_db4.sh
index cfc29654cb..6c6577de33 100755
--- a/contrib/install_db4.sh
+++ b/contrib/install_db4.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 # Copyright (c) 2017-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or https://opensource.org/licenses/mit-license.php.
@@ -20,6 +20,10 @@ expand_path() {
   cd "${1}" && pwd -P
 }
 
+prev_dir=$(pwd)
+script_dir=$(expand_path $(dirname ${0}))
+cd "${prev_dir}"
+
 BDB_PREFIX="$(expand_path ${1})/db4"; shift;
 BDB_VERSION='db-4.8.30.NC'
 BDB_HASH='12edc0df75bf9abd7f82f821795bcee50f42cb2e5f76a6a281b85732798364ef'
@@ -221,19 +225,15 @@ EOF
 # The packaged config.guess and config.sub are ancient (2009) and can cause build issues.
 # Replace them with modern versions.
 # See https://github.com/bitcoin/bitcoin/issues/16064
-CONFIG_GUESS_URL='https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=55eaf3e779455c4e5cc9f82efb5278be8f8f900b'
-CONFIG_GUESS_HASH='2d1ff7bca773d2ec3c6217118129220fa72d8adda67c7d2bf79994b3129232c1'
-CONFIG_SUB_URL='https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=55eaf3e779455c4e5cc9f82efb5278be8f8f900b'
-CONFIG_SUB_HASH='3a4befde9bcdf0fdb2763fc1bfa74e8696df94e1ad7aac8042d133c8ff1d2e32'
-
 rm -f "dist/config.guess"
 rm -f "dist/config.sub"
 
-http_get "${CONFIG_GUESS_URL}" dist/config.guess "${CONFIG_GUESS_HASH}"
-http_get "${CONFIG_SUB_URL}" dist/config.sub "${CONFIG_SUB_HASH}"
+cp "$script_dir/../depends/config.guess" dist/config.guess
+cp "$script_dir/../depends/config.sub" dist/config.sub
 
 cd build_unix/
 
+CFLAGS="$CFLAGS -Wno-error=implicit-function-declaration" \
 "${BDB_PREFIX}/${BDB_VERSION}/dist/configure" \
   --enable-cxx --disable-shared --disable-replication --with-pic --prefix="${BDB_PREFIX}" \
   "${@}"