diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7695dd440d2d2885ec221a0bb44f43bae613f86f..756c329d636ea3d03d81c8802eae2d46c89aaa72 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -109,8 +109,9 @@ if(WITH_GUI)
 endif()
 
 
-# NOTE: leading / is important other whole path will be installed.
-install(DIRECTORY ${PYMOOSE_INSTALL_DIR}/
+# NOTE: leading / is important other whole path will be installed. Do not
+# install usr since it comes with CMAKE_INSTALL_PREFIX.
+install(DIRECTORY ${PYMOOSE_INSTALL_DIR}/usr/
     DESTINATION ${CMAKE_INSTALL_PREFIX}
     CONFIGURATIONS Release
     PATTERN ".git" EXCLUDE