diff --git a/ext/hal/silabs/gecko/CMakeLists.txt b/ext/hal/silabs/gecko/CMakeLists.txt
index 84dea5d906..a95085d145 100644
--- a/ext/hal/silabs/gecko/CMakeLists.txt
+++ b/ext/hal/silabs/gecko/CMakeLists.txt
@@ -34,3 +34,4 @@ zephyr_sources_ifdef(CONFIG_SOC_SERIES_EFM32WG     Device/SiliconLabs/EFM32WG/So
 zephyr_sources_ifdef(CONFIG_SOC_SERIES_EFR32FG1P   Device/SiliconLabs/EFR32FG1P/Source/system_efr32fg1p.c)
 zephyr_sources_ifdef(CONFIG_SOC_SERIES_EFM32HG     Device/SiliconLabs/EFM32HG/Source/system_efm32hg.c)
 zephyr_sources_ifdef(CONFIG_SOC_SERIES_EFR32MG12P  Device/SiliconLabs/EFR32MG12P/Source/system_efr32mg12p.c)
+zephyr_sources_ifdef(CONFIG_SOC_SERIES_EFM32PG12B  Device/SiliconLabs/EFM32PG12B/Source/system_efm32pg12b.c)