diff --git a/os/hal/ports/STM32/STM32F1xx/platform.mk b/os/hal/ports/STM32/STM32F1xx/platform.mk
index 9a2fca831..216724585 100644
--- a/os/hal/ports/STM32/STM32F1xx/platform.mk
+++ b/os/hal/ports/STM32/STM32F1xx/platform.mk
@@ -17,8 +17,8 @@ ifneq ($(findstring HAL_USE_ADC TRUE,$(HALCONF)),)
 PLATFORMSRC += $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_adc_lld.c
 endif
 else
+PLATFORMSRC += $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_ext_lld_isr.c \
                $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_adc_lld.c
-PLATFORMSRC += $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_ext_lld_isr.c
 endif
 
 # Drivers compatible with the platform.
diff --git a/os/hal/ports/STM32/STM32F1xx/platform_f105_f107.mk b/os/hal/ports/STM32/STM32F1xx/platform_f105_f107.mk
index 3b2a4168a..8c4eb980e 100644
--- a/os/hal/ports/STM32/STM32F1xx/platform_f105_f107.mk
+++ b/os/hal/ports/STM32/STM32F1xx/platform_f105_f107.mk
@@ -17,8 +17,8 @@ ifneq ($(findstring HAL_USE_ADC TRUE,$(HALCONF)),)
 PLATFORMSRC += $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_adc_lld.c
 endif
 else
+PLATFORMSRC += $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_ext_lld_isr.c \
                $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_adc_lld.c
-PLATFORMSRC += $(CHIBIOS)/os/hal/ports/STM32/STM32F1xx/hal_ext_lld_isr.c
 endif
 
 # Drivers compatible with the platform.