diff --git a/ExtLibraries/CMakeLists.txt b/ExtLibraries/CMakeLists.txt
index 062e93ccd..1723ecb87 100644
--- a/ExtLibraries/CMakeLists.txt
+++ b/ExtLibraries/CMakeLists.txt
@@ -16,8 +16,13 @@ if(NOT DEFINED EXT_LIB_DIR)
   set(EXT_LIB_DIR "${CMAKE_CURRENT_LIST_DIR}/../../ExtLibraries/")
 endif()
 
+if(NOT DEFINED SETTINGS_DIR)
+  set(SETTINGS_DIR "${CMAKE_CURRENT_LIST_DIR}/../settings/")
+endif()
+
 # windows path
 string(REPLACE "\\" "/" EXT_LIB_DIR ${EXT_LIB_DIR})
+string(REPLACE "\\" "/" SETTINGS_DIR ${SETTINGS_DIR})
 
 message("ExtLibraries install dir: ${EXT_LIB_DIR}")
 
diff --git a/ExtLibraries/cspice/CMakeLists.txt b/ExtLibraries/cspice/CMakeLists.txt
index 570dbb844..68247c39b 100644
--- a/ExtLibraries/cspice/CMakeLists.txt
+++ b/ExtLibraries/cspice/CMakeLists.txt
@@ -8,7 +8,6 @@ include(FetchContent)
 set(CSPICE_INSTALL_DIR ${EXT_LIB_DIR}/cspice)
 set(GENERIC_KERNEL_URL_BASE https://naif.jpl.nasa.gov/pub/naif/generic_kernels)
 
-set(SETTINGS_DIR "${CMAKE_CURRENT_LIST_DIR}/../../settings/")
 set(GENERIC_KERNEL_INSTALL_DIR ${SETTINGS_DIR}/environment/cspice)
 
 if(WIN32)
diff --git a/ExtLibraries/lunar_gravity_field/CMakeLists.txt b/ExtLibraries/lunar_gravity_field/CMakeLists.txt
index 2c5f75c56..271b1faa9 100644
--- a/ExtLibraries/lunar_gravity_field/CMakeLists.txt
+++ b/ExtLibraries/lunar_gravity_field/CMakeLists.txt
@@ -4,8 +4,6 @@ cmake_minimum_required(VERSION 3.18)
 
 include(FetchContent)
 
-set(SETTINGS_DIR "${CMAKE_CURRENT_LIST_DIR}/../../settings/")
-
 set(LUNAR_GRAVITY_FIELD_INSTALL_DIR ${SETTINGS_DIR}/environment/gravity_field)
 
 set(LUNAR_GRAVITY_FIELD_URL_BASE https://pds-geosciences.wustl.edu/grail/grail-l-lgrs-5-rdr-v1/grail_1001/shadr)
diff --git a/ExtLibraries/nrlmsise00/CMakeLists.txt b/ExtLibraries/nrlmsise00/CMakeLists.txt
index cb256c8d2..ee49b64d9 100644
--- a/ExtLibraries/nrlmsise00/CMakeLists.txt
+++ b/ExtLibraries/nrlmsise00/CMakeLists.txt
@@ -5,8 +5,6 @@ cmake_minimum_required(VERSION 3.18)
 include(ExternalProject)
 include(FetchContent)
 
-set(SETTINGS_DIR "${CMAKE_CURRENT_LIST_DIR}/../../settings/")
-
 set(NRLMSISE_INSTALL_DIR ${EXT_LIB_DIR}/nrlmsise00)
 set(TABLE_FILE_INSTALL_DIR ${SETTINGS_DIR}/environment/space_weather)