diff --git a/cov.sh b/cov.sh
index 66aa8c762..c63687acf 100755
--- a/cov.sh
+++ b/cov.sh
@@ -16,10 +16,11 @@ if ! type kcov > /dev/null; then
 fi
 
 cargo test -p ethash -p ethcore-util -p ethcore -p ethsync -p ethcore-rpc -p parity --no-run || exit $?
+rm -rf target/coverage
 mkdir -p target/coverage
-kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1 --include-pattern src --verify target/coverage target/debug/deps/ethcore-*
-kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1 --include-pattern src --verify target/coverage target/debug/deps/ethash-*
-kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1 --include-pattern src --verify target/coverage target/debug/deps/ethcore_util-*
-kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1 --include-pattern src --verify target/coverage target/debug/deps/ethsync-*
-kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1 --include-pattern src --verify target/coverage target/debug/deps/ethcore_rpc-*
+kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1,src/tests --include-pattern src --verify target/coverage target/debug/deps/ethcore-*
+kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1,src/tests --include-pattern src --verify target/coverage target/debug/deps/ethash-*
+kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1,src/tests --include-pattern src --verify target/coverage target/debug/deps/ethcore_util-*
+kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1,src/tests --include-pattern src --verify target/coverage target/debug/deps/ethsync-*
+kcov --exclude-pattern ~/.multirust,rocksdb,secp256k1,src/tests --include-pattern src --verify target/coverage target/debug/deps/ethcore_rpc-*
 xdg-open target/coverage/index.html