diff --git a/Marlin/src/HAL/STM32F1/HAL.cpp b/Marlin/src/HAL/STM32F1/HAL.cpp
index 1d58b106adfd..636dc742fcf5 100644
--- a/Marlin/src/HAL/STM32F1/HAL.cpp
+++ b/Marlin/src/HAL/STM32F1/HAL.cpp
@@ -335,7 +335,7 @@ void MarlinHAL::adc_start(const pin_t pin) {
     _TCASE(POWER_MONITOR_CURRENT, POWER_MONITOR_CURRENT_PIN, POWERMON_CURRENT)
     _TCASE(POWER_MONITOR_VOLTAGE, POWER_MONITOR_VOLTAGE_PIN, POWERMON_VOLTS)
   }
-  adc_result = adc_results[(int)pin_index] >> (12 - HAL_ADC_RESOLUTION); // shift out unused bits
+  adc_result = (adc_results[(int)pin_index] & 0xFFF) >> (12 - HAL_ADC_RESOLUTION); // shift out unused bits
 }
 
 #endif // __STM32F1__
diff --git a/ini/stm32-common.ini b/ini/stm32-common.ini
index 54bc746ff4ff..1d3f858bf8e9 100644
--- a/ini/stm32-common.ini
+++ b/ini/stm32-common.ini
@@ -16,6 +16,7 @@ build_flags      = ${common.build_flags}
                    -std=gnu++14 -DHAL_STM32
                    -DUSBCON -DUSBD_USE_CDC
                    -DTIM_IRQ_PRIO=13
+                   -DADC_RESOLUTION=12
 build_unflags    = -std=gnu++11
 src_filter       = ${common.default_src_filter} +<src/HAL/STM32> +<src/HAL/shared/backtrace>
 extra_scripts    = ${common.extra_scripts}
diff --git a/ini/stm32g0.ini b/ini/stm32g0.ini
index 171945ffe2f0..e6094c1e312d 100644
--- a/ini/stm32g0.ini
+++ b/ini/stm32g0.ini
@@ -30,7 +30,6 @@ board                       = marlin_STM32G0B1RE
 board_build.offset          = 0x2000
 board_upload.offset_address = 0x08002000
 build_flags                 = ${stm32_variant.build_flags}
-                            -DADC_RESOLUTION=12
                             -DPIN_SERIAL4_RX=PC_11 -DPIN_SERIAL4_TX=PC_10
                             -DSERIAL_RX_BUFFER_SIZE=1024 -DSERIAL_TX_BUFFER_SIZE=1024
                             -DTIMER_SERVO=TIM3 -DTIMER_TONE=TIM4