diff --git a/audio_to_spectrogram/CMakeLists.txt b/audio_to_spectrogram/CMakeLists.txt
index f3828e9d70..a20760df5f 100644
--- a/audio_to_spectrogram/CMakeLists.txt
+++ b/audio_to_spectrogram/CMakeLists.txt
@@ -17,7 +17,7 @@ install(DIRECTORY launch sample test
   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
   USE_SOURCE_PERMISSIONS
 )
-if(NOT $ENV{ROS_DISTRO} STREQUAL "indigo") # on noetic it needs catkin_install_python to support Python3 and it does not work on indigo for some reason...
+if($ENV{ROS_DISTRO} STREQUAL "indigo") # on noetic it needs catkin_install_python to support Python3 and it does not work on indigo for some reason...
   install(DIRECTORY scripts
     DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
     USE_SOURCE_PERMISSIONS