diff --git a/run.sh b/run.sh
index 7d3faeb..e27f064 100755
--- a/run.sh
+++ b/run.sh
@@ -36,18 +36,18 @@ if [ "$1" = "import" ]; then
     setPostgresPassword
 
     # Download Luxembourg as sample if no data is provided
-    if [ ! -f /data.osm.pbf && ! -z "$(DL_PBF)" ]; then
+    if [ ! -f /data.osm.pbf ] && [ -z "$DL_PBF" ]; then
 		echo "WARNING: No import file at /data.osm.pbf, so importing Luxembourg as example..."
 		DL_PBF="http://download.geofabrik.de/europe/luxembourg-latest.osm.pbf"
 		DL_PBF_POLY="http://download.geofabrik.de/europe/luxembourg.poly"
     fi
 	
-	if [ -z "$(DL_PBF)" ]; then
+	if [ -n "$DL_PBF" ]; then
 		echo "INFO: Download PBF file: $DL_PBF"
-		wget -nv "$(DL_PBF)" -O /data.osm.pbf
-		if [ -z "$(DL_PBF_POLY)" ]; then
-			echo "INFO: Download PBF-POLY file: $(DL_PBF_POLY)"
-			wget -nv "$(DL_PBF_POLY)" -O /data.poly
+		wget -nv "$DL_PBF" -O /data.osm.pbf
+		if [ -n "$DL_PBF_POLY" ]; then
+			echo "INFO: Download PBF-POLY file: $DL_PBF_POLY"
+			wget -nv "$DL_PBF_POLY" -O /data.poly
 		fi
 	fi