diff --git a/.travis/ci-system-setup.sh b/.travis/ci-system-setup.sh
index b381f2685c..25e7fb193f 100755
--- a/.travis/ci-system-setup.sh
+++ b/.travis/ci-system-setup.sh
@@ -15,11 +15,11 @@ then
     if [ `uname` = "Darwin" ]
     then
         sysctl -n machdep.cpu.brand_string
-        brew install coreutils python3 numpy python-setuptools
+        brew install coreutils python3 numpy python-setuptools jshon
         PATH="/opt/homebrew/opt/coreutils/libexec/gnubin:$PATH"
         export PYTHON_BIN_PATH=python3
     else
-        sudo apt-get install -y llvm python3 python3-numpy
+        sudo apt-get install -y llvm python3 python3-numpy jshon
     fi
     touch .setup-done
 fi
diff --git a/api/proxy/ci.sh b/api/proxy/ci.sh
index b12a4740a6..507e856d51 100755
--- a/api/proxy/ci.sh
+++ b/api/proxy/ci.sh
@@ -4,9 +4,11 @@ ROOT=$(dirname $(realpath $0))/../..
 
 set -ex
 
-cargo build --release -p tract-ffi
-export TRACT_DYLIB_SEARCH_PATH=$ROOT/target/release
-export LD_LIBRARY_PATH=$ROOT/target/release
+cargo build --release -p tract-ffi $CARGO_EXTRA
+SO=$(cargo build  --message-format=json --release -p tract-ffi $CARGO_EXTRA | grep cdylib | jshon -e  filenames -e 0 -u)
+SO_PATH=$(dirname $SO)
+export TRACT_DYLIB_SEARCH_PATH=$SO_PATH
+export LD_LIBRARY_PATH=$SO_PATH
 
 cd $(dirname $(realpath $0))
-cargo test
+cargo test $CARGO_EXTRA