diff --git a/src/Plugins/OrientationAnalysis/CMakeLists.txt b/src/Plugins/OrientationAnalysis/CMakeLists.txt
index 76bf09b200..f2d6825b79 100644
--- a/src/Plugins/OrientationAnalysis/CMakeLists.txt
+++ b/src/Plugins/OrientationAnalysis/CMakeLists.txt
@@ -245,7 +245,6 @@ set(PLUGIN_EXTRA_SOURCES
   "${${PLUGIN_NAME}_SOURCE_DIR}/src/${PLUGIN_NAME}/utilities/TiffWriter.cpp"
   "${${PLUGIN_NAME}_SOURCE_DIR}/src/${PLUGIN_NAME}/utilities/delaunator.cpp"
   "${${PLUGIN_NAME}_SOURCE_DIR}/src/${PLUGIN_NAME}/utilities/delaunator.h"
-  "${${PLUGIN_NAME}_SOURCE_DIR}/src/${PLUGIN_NAME}/utilities/RTree.hpp"
   "${${PLUGIN_NAME}_SOURCE_DIR}/src/${PLUGIN_NAME}/utilities/IntersectionUtilities.hpp"
 )
 target_sources(${PLUGIN_NAME} PRIVATE ${PLUGIN_EXTRA_SOURCES})