diff --git a/.gn b/.gn
index b00e806..a7f2d75 100644
--- a/.gn
+++ b/.gn
@@ -17,4 +17,7 @@
 default_args = {
   # Set the nanopb directory for protobuf generation.
   dir_pw_third_party_nanopb = "//third_party/nanopb"
+
+  # Sets the FreeRTOS source directory.
+  dir_pw_third_party_freertos = "//third_party/freertos/Source"
 }
diff --git a/targets/stm32f439zi_nucleo/target_toolchains.gni b/targets/stm32f439zi_nucleo/target_toolchains.gni
index b584c24..d235ad0 100644
--- a/targets/stm32f439zi_nucleo/target_toolchains.gni
+++ b/targets/stm32f439zi_nucleo/target_toolchains.gni
@@ -82,7 +82,6 @@
   pw_third_party_stm32cube_CONFIG =
       "//targets/stm32f439zi_nucleo:stm32f4xx_hal_config"
 
-  dir_pw_third_party_freertos = "//third_party/freertos"
   pw_third_party_freertos_CONFIG =
       "//targets/stm32f439zi_nucleo:freertos_config"
   pw_third_party_freertos_PORT = "//third_party/freertos:arm_cm4f_freertos_port"