diff -up meshlab-Meshlab-2021.07/src/CMakeLists.txt.libdirfix meshlab-Meshlab-2021.07/src/CMakeLists.txt
--- meshlab-Meshlab-2021.07/src/CMakeLists.txt.libdirfix	2021-09-20 13:53:47.095514858 -0400
+++ meshlab-Meshlab-2021.07/src/CMakeLists.txt	2021-09-20 13:55:06.602952041 -0400
@@ -50,8 +50,8 @@ if (USE_DEFAULT_BUILD_AND_INSTALL_DIRS)
 	include(GNUInstallDirs)
 	if(INSTALL_TO_UNIX_LAYOUT)
 		set(MESHLAB_BIN_INSTALL_DIR ${CMAKE_INSTALL_BINDIR})
-		set(MESHLAB_LIB_INSTALL_DIR ${CMAKE_INSTALL_LIBDIR}/meshlab)
-		set(MESHLAB_PLUGIN_INSTALL_DIR ${MESHLAB_LIB_INSTALL_DIR}/plugins)
+		set(MESHLAB_LIB_INSTALL_DIR ${CMAKE_INSTALL_LIBDIR})
+		set(MESHLAB_PLUGIN_INSTALL_DIR ${MESHLAB_LIB_INSTALL_DIR}/meshlab/plugins)
 		set(MESHLAB_SHADER_INSTALL_DIR ${CMAKE_INSTALL_DATAROOTDIR}/meshlab/shaders)
 	elseif(APPLE)
 		set(MESHLAB_BIN_INSTALL_DIR .)