diff --git a/projects/bignum-fuzzer/Dockerfile b/projects/bignum-fuzzer/Dockerfile
index 4fcced626..ba08d04f8 100644
--- a/projects/bignum-fuzzer/Dockerfile
+++ b/projects/bignum-fuzzer/Dockerfile
@@ -19,7 +19,7 @@ RUN apt-get update && apt-get install -y software-properties-common python-softw
 RUN add-apt-repository -y ppa:gophers/archive && apt-get update && apt-get install -y golang-1.9-go
 RUN ln -s /usr/lib/go-1.9/bin/go /usr/bin/go
 
-RUN wget https://www.bytereef.org/software/mpdecimal/releases/mpdecimal-2.4.2.tar.gz
+RUN wget https://www.bytereef.org/software/mpdecimal/releases/mpdecimal-2.5.0.tar.gz
 RUN git clone --recursive https://github.com/golang/go
 RUN git clone --depth 1 https://github.com/guidovranken/bignum-fuzzer
 RUN git clone --depth 1 https://github.com/openssl/openssl
diff --git a/projects/bignum-fuzzer/build.sh b/projects/bignum-fuzzer/build.sh
index f0ac9f3ae..699c3fa4e 100755
--- a/projects/bignum-fuzzer/build.sh
+++ b/projects/bignum-fuzzer/build.sh
@@ -1,3 +1,20 @@
+#!/bin/bash -eu
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+################################################################################
+
 # Compile latest Go
 cd go/src
 ./make.bash
@@ -14,8 +31,8 @@ export PATH=`realpath $SRC/go/bin`:$PATH
 #source $HOME/.cargo/env
 
 # Build libmpdec
-tar zxf mpdecimal-2.4.2.tar.gz
-cd mpdecimal-2.4.2
+tar zxf mpdecimal-2.5.0.tar.gz
+cd mpdecimal-2.5.0
 ./configure && make -j$(nproc)
 
 cd $SRC/openssl
@@ -54,7 +71,7 @@ LIBGMP_INCLUDE_PATH=$SRC/libgmp LIBGMP_A_PATH=$SRC/libgmp/.libs/libgmp.a make
 
 # Build libmpdec module
 cd $SRC/bignum-fuzzer/modules/libmpdec
-LIBMPDEC_A_PATH=$SRC/mpdecimal-2.4.2/libmpdec/libmpdec.a LIBMPDEC_INCLUDE_PATH=$SRC/mpdecimal-2.4.2/libmpdec make
+LIBMPDEC_A_PATH=$SRC/mpdecimal-2.5.0/libmpdec/libmpdec.a LIBMPDEC_INCLUDE_PATH=$SRC/mpdecimal-2.5.0/libmpdec make
 
 BASE_CXXFLAGS=$CXXFLAGS