use -n instead of ! -z
diff --git a/.travis/install.sh b/.travis/install.sh
index f04c2ff..a4f99be 100755
--- a/.travis/install.sh
+++ b/.travis/install.sh
@@ -69,7 +69,7 @@
         OPENSSL_DIR="ossl-098l"
     fi
     # download, compile, and install if it's not already present via travis cache
-    if [ ! -z "$OPENSSL_DIR" ]; then
+    if [ -n "$OPENSSL_DIR" ]; then
         if [[ ! -f "$HOME/$OPENSSL_DIR/bin/openssl" ]]; then
             curl -O https://www.openssl.org/source/openssl-$OPENSSL_VERSION_NUMBER.tar.gz
             tar zxf openssl-$OPENSSL_VERSION_NUMBER.tar.gz
diff --git a/.travis/run.sh b/.travis/run.sh
index c8707a4..9731e20a 100755
--- a/.travis/run.sh
+++ b/.travis/run.sh
@@ -27,7 +27,7 @@
         OPENSSL_DIR="ossl-098l"
     fi
 
-    if [ ! -z "$OPENSSL_DIR" ]; then
+    if [ -n "$OPENSSL_DIR" ]; then
         export PATH="$HOME/$OPENSSL_DIR/bin:$PATH"
         export CFLAGS="-I$HOME/$OPENSSL_DIR/include"
         # rpath on linux will cause it to use an absolute path so we don't need to do LD_LIBRARY_PATH