diff --git a/subsys/bluetooth/controller/ll_sw/nrf.cmake b/subsys/bluetooth/controller/ll_sw/nrf.cmake
index 38600530cb4..6e3033e109f 100644
--- a/subsys/bluetooth/controller/ll_sw/nrf.cmake
+++ b/subsys/bluetooth/controller/ll_sw/nrf.cmake
@@ -56,10 +56,9 @@ if(CONFIG_BT_LL_SW_SPLIT)
     CONFIG_BT_CTLR_DF
     ll_sw/nordic/lll/lll_df.c
     )
-  zephyr_library_sources_ifdef(
-    (CONFIG_BT_CTLR_DF AND NOT CONFIG_SOC_SERIES_BSIM_NRFXX)
+  if(CONFIG_BT_CTLR_DF AND NOT CONFIG_SOC_SERIES_BSIM_NRFXX)
     zephyr_library_sources(ll_sw/nordic/hal/nrf5/radio/radio_df.c)
-    )
+  endif()
   zephyr_library_include_directories(
     ll_sw/nordic/lll
     )