diff --git a/jsk_rosbag_tools/CMakeLists.txt b/jsk_rosbag_tools/CMakeLists.txt
index b52a9bb29..445533776 100644
--- a/jsk_rosbag_tools/CMakeLists.txt
+++ b/jsk_rosbag_tools/CMakeLists.txt
@@ -18,7 +18,7 @@ catkin_package(
   CATKIN_DEPENDS
 )
 
-if($ENV{ROS_DISTRO} STREQUAL "indigo" OR $ENV{ROS_DISTRO} STREQUAL "kinetic" OR $ENV{ROS_DISTRO} STREQUAL "melodic")
+if("$ENV{ROS_DISTRO}" STREQUAL "indigo" OR "$ENV{ROS_DISTRO}" STREQUAL "kinetic" OR "$ENV{ROS_DISTRO}" STREQUAL "melodic")
   catkin_generate_virtualenv(
     INPUT_REQUIREMENTS requirements.in.python2
     PYTHON_INTERPRETER python2