diff --git a/cpp/cmake/templates/dolfinx.conf.in b/cpp/cmake/templates/dolfinx.conf.in
index 02bd8e4f82..36fcae00f7 100644
--- a/cpp/cmake/templates/dolfinx.conf.in
+++ b/cpp/cmake/templates/dolfinx.conf.in
@@ -1,10 +1,10 @@
 # Helper file for setting non-default DOLFINx environment variables
 
 # Common Unix variables
-export @OS_LIBRARY_PATH_NAME@=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@:$@OS_LIBRARY_PATH_NAME@
-export PATH=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_BINDIR@:$PATH
-export PKG_CONFIG_PATH=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/pkgconfig:$PKG_CONFIG_PATH
-export CMAKE_PREFIX_PATH=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/cmake:$CMAKE_PREFIX_PATH
+export @OS_LIBRARY_PATH_NAME@=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@:${@OS_LIBRARY_PATH_NAME@:-}
+export PATH=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_BINDIR@:${PATH:-}
+export PKG_CONFIG_PATH=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/pkgconfig:${PKG_CONFIG_PATH:-}
+export CMAKE_PREFIX_PATH=@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/cmake:${CMAKE_PREFIX_PATH:-}
 
 # Special macOS variables
-export DYLD_FRAMEWORK_PATH=/opt/local/Library/Frameworks:$DYLD_FRAMEWORK_PATH
+export DYLD_FRAMEWORK_PATH=/opt/local/Library/Frameworks:${DYLD_FRAMEWORK_PATH:-}