diff --git a/nss/Dockerfile b/nss/Dockerfile
index 48edb00e3..d3359b410 100644
--- a/nss/Dockerfile
+++ b/nss/Dockerfile
@@ -18,6 +18,9 @@ FROM ossfuzz/base-libfuzzer
 MAINTAINER mmoroz@chromium.org
 RUN apt-get install -y make autoconf automake libtool mercurial zlib1g-dev
 
-RUN hg clone https://hg.mozilla.org/projects/nspr
-RUN hg clone https://hg.mozilla.org/projects/nss
+# Need to create 'work' subdir for nss and nspr sources, because '/src/nss' is
+# occupied by oss-fuzz sources checked out using dummy path from Jenkinsfile.
+RUN mkdir -p work
+RUN hg clone https://hg.mozilla.org/projects/nspr work/nspr
+RUN hg clone https://hg.mozilla.org/projects/nss work/nss
 COPY build.sh fuzzers/* /src/
diff --git a/nss/build.sh b/nss/build.sh
index 2a49936be..8a6f4893f 100755
--- a/nss/build.sh
+++ b/nss/build.sh
@@ -16,9 +16,8 @@
 ################################################################################
 
 # Build the library.
-cd /work/nss/nss
-make BUILD_OPT=1 USE_64=1 NSS_DISABLE_GTESTS=1 CC="$CC $CFLAGS" \
-    CXX="$CXX $CXXFLAGS" LD="$CC $CFLAGS" ZDEFS_FLAG= clean nss_build_all
+cd work/nss
+make BUILD_OPT=1 USE_64=1 NSS_DISABLE_GTESTS=1 ZDEFS_FLAG= clean nss_build_all
 cd ..
 
 # Copy libraries and some objects to /work/nss/lib.