diff --git a/arch/arm/src/stm32l5/stm32l5_rcc.h b/arch/arm/src/stm32l5/stm32l5_rcc.h
index d9e1cd1fee..872732541a 100644
--- a/arch/arm/src/stm32l5/stm32l5_rcc.h
+++ b/arch/arm/src/stm32l5/stm32l5_rcc.h
@@ -47,7 +47,7 @@
 #define EXTERN extern "C"
 extern "C"
 {
-#elseO
+#else
 #define EXTERN extern
 #endif