diff --git a/qrenderdoc/CMakeLists.txt b/qrenderdoc/CMakeLists.txt
index 2df9ffa5..66bafaba 100644
--- a/qrenderdoc/CMakeLists.txt
+++ b/qrenderdoc/CMakeLists.txt
@@ -65,16 +65,6 @@ include(ExternalProject)
 # Need bison for swig
 find_package(BISON)
 
-# Compile our custom SWIG that will do scoped/strong enum classes
-ExternalProject_Add(custom_swig
-    # using an URL to a zip directly so we don't clone the history etc
-    URL ${RENDERDOC_SWIG_PACKAGE}
-    BUILD_IN_SOURCE 1
-    CONFIGURE_COMMAND ./autogen.sh > /dev/null 2>&1
-    COMMAND CC=${CMAKE_C_COMPILER} CXX=${CMAKE_CXX_COMPILER} ./configure --with-pcre=yes --prefix=${CMAKE_BINARY_DIR} > /dev/null
-    BUILD_COMMAND $(MAKE) > /dev/null 2>&1
-    INSTALL_COMMAND $(MAKE) install > /dev/null 2>&1)
-
 # Lastly find PySide 2, optionally, for Qt5 Python bindings
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}")
 
@@ -186,9 +176,8 @@ foreach(in ${swig_interfaces})
     get_filename_component(swig_file ${in} NAME_WE)
 
     add_custom_command(OUTPUT ${swig_file}_python.cxx ${swig_file}.py
-            COMMAND ${CMAKE_BINARY_DIR}/bin/swig -v -Wextra -Werror -O -c++ -python -modern -modernargs -enumclass -fastunpack -py3 -builtin -I${CMAKE_CURRENT_SOURCE_DIR} -I${CMAKE_SOURCE_DIR}/renderdoc/api/replay -outdir ${CMAKE_CURRENT_BINARY_DIR} -o ${CMAKE_CURRENT_BINARY_DIR}/${swig_file}_python.cxx ${CMAKE_CURRENT_SOURCE_DIR}/${in}
+	    COMMAND $ENV{NIXOS_CUSTOM_SWIG} -v -Wextra -Werror -O -c++ -python -modern -modernargs -enumclass -fastunpack -py3 -builtin -I${CMAKE_CURRENT_SOURCE_DIR} -I${CMAKE_SOURCE_DIR}/renderdoc/api/replay -outdir ${CMAKE_CURRENT_BINARY_DIR} -o ${CMAKE_CURRENT_BINARY_DIR}/${swig_file}_python.cxx ${CMAKE_CURRENT_SOURCE_DIR}/${in}
             DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${in}
-            DEPENDS custom_swig
             DEPENDS ${RDOC_REPLAY_FILES}
             DEPENDS ${QRD_INTERFACE_FILES})