diff --git a/boards.txt b/boards.txt
index 47a452a2c9..8f0141a3e6 100644
--- a/boards.txt
+++ b/boards.txt
@@ -633,6 +633,22 @@ Nucleo_64.menu.pnum.NUCLEO_F030R8.build.variant=STM32F0xx/F030R8T
 Nucleo_64.menu.pnum.NUCLEO_F030R8.openocd.target=stm32f0x
 Nucleo_64.menu.pnum.NUCLEO_F030R8.debug.svd_file={runtime.tools.STM32_SVD.path}/svd/STM32F0xx/STM32F0x0.svd
 
+# NUCLEO_F030R8 with internal HSI clock (including MB1136 C-01)
+# Docs: url=https://www.st.com/en/evaluation-tools/nucleo-f030r8.html
+# Docs: notes=Internal HSI / 2 x 12 = 48 MHz; suitable for MB1136 C-01 without ST-LINK MCO.
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI=Nucleo F030R8 (HSI, 48 MHz)
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.node="NODE_F030R8,NUCLEO"
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.upload.maximum_size=65536
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.upload.maximum_data_size=8192
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.build.mcu=cortex-m0
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.build.board=NUCLEO_F030R8
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.build.series=STM32F0xx
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.build.product_line=STM32F030x8
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.build.variant=STM32F0xx/F030R8T
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.openocd.target=stm32f0x
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.debug.svd_file={runtime.tools.STM32_SVD.path}/svd/STM32F0xx/STM32F0x0.svd
+Nucleo_64.menu.pnum.NUCLEO_F030R8_HSI.build.st_extra_flags=-D{build.product_line} {build.enable_usb} {build.xSerial} -DNUCLEO_F030R8_USE_HSI
+
 # NUCLEO_F070RB board
 # Docs: release=2.0.0
 # Docs: url=http://www.st.com/en/evaluation-tools/nucleo-f070rb.html
diff --git a/docs/customization/Custom-definitions.md b/docs/customization/Custom-definitions.md
index 318ea964a3..c64672250e 100644
--- a/docs/customization/Custom-definitions.md
+++ b/docs/customization/Custom-definitions.md
@@ -278,6 +278,14 @@ extern "C" void SystemClock_Config() {
 }
 ```
 
+### NUCLEO-F030R8 clock source
+
+For a NUCLEO-F030R8 without an external HSE clock, select **Nucleo F030R8 (HSI, 48 MHz)** under **Tools > Board part number**. This uses the internal 8 MHz HSI oscillator divided by 2 and multiplied by 12, giving a nominal 48 MHz system clock. No sketch changes are required.
+
+The existing **Nucleo F030R8** option continues to use an 8 MHz external clock in HSE bypass mode, normally provided by ST-LINK MCO, multiplied by 6 to reach 48 MHz. Both options share the same pin mapping, memory layout, upload methods and debugger configuration.
+
+[UM1724, section 7.9.1](https://www.st.com/resource/en/user_manual/dm00105823.pdf) documents MB1136 C-01 as configured with HSE not used, and C-02 or higher as configured with ST-LINK MCO connected. Choose the option that matches the actual clock wiring, which can differ after solder-bridge modifications. The internal HSI oscillator has lower frequency accuracy than a suitable external clock source; consider this for applications with strict timing requirements.
+
 ## Enable UCPD dead battery behavior
 
 > [!NOTE]
diff --git a/docs/supported-boards/index.md b/docs/supported-boards/index.md
index 606b734b9c..e2c74c8ef2 100644
--- a/docs/supported-boards/index.md
+++ b/docs/supported-boards/index.md
@@ -47,6 +47,7 @@
 | [Nucleo C092RC](https://www.st.com/en/evaluation-tools/nucleo-c092rc.html) | [STM32C092RC](https://www.st.com/en/microcontrollers-microprocessors/stm32c092rc.html) | `NUCLEO_C092RC` | 2.11.0 |  |
 | [Nucleo C562RE](https://www.st.com/en/evaluation-tools/stm32-nucleo-boards.html) | [STM32C562RE](https://www.st.com/en/microcontrollers-microprocessors/stm32c562re.html) | `NUCLEO_C562RE` | 3.0.0 |  |
 | [Nucleo F030R8](http://www.st.com/en/evaluation-tools/nucleo-f030r8.html) | [STM32F030R8](https://www.st.com/en/microcontrollers-microprocessors/stm32f030r8.html) | `NUCLEO_F030R8` | 0.2.0 |  |
+| [Nucleo F030R8 (HSI, 48 MHz)](https://www.st.com/en/evaluation-tools/nucleo-f030r8.html) | [STM32F030R8](https://www.st.com/en/microcontrollers-microprocessors/stm32f030r8.html) | `NUCLEO_F030R8` | Next release | Internal HSI / 2 x 12 = 48 MHz; suitable for MB1136 C-01 without ST-LINK MCO. |
 | [Nucleo F070RB](http://www.st.com/en/evaluation-tools/nucleo-f070rb.html) | [STM32F070RB](https://www.st.com/en/microcontrollers-microprocessors/stm32f070rb.html) | `NUCLEO_F070RB` | 2.0.0 |  |
 | [Nucleo F072RB](http://www.st.com/en/evaluation-tools/nucleo-f072rb.html) | [STM32F072RB](https://www.st.com/en/microcontrollers-microprocessors/stm32f072rb.html) | `NUCLEO_F072RB` | 1.9.0 |  |
 | [Nucleo F091RC](http://www.st.com/en/evaluation-tools/nucleo-f091rc.html) | [STM32F091RC](https://www.st.com/en/microcontrollers-microprocessors/stm32f091rc.html) | `NUCLEO_F091RC` | 0.1.0 |  |
diff --git a/variants/STM32F0xx/F030R8T/variant_NUCLEO_F030R8.cpp b/variants/STM32F0xx/F030R8T/variant_NUCLEO_F030R8.cpp
index e8aa39d827..97caaede1f 100644
--- a/variants/STM32F0xx/F030R8T/variant_NUCLEO_F030R8.cpp
+++ b/variants/STM32F0xx/F030R8T/variant_NUCLEO_F030R8.cpp
@@ -117,11 +117,22 @@ WEAK void SystemClock_Config(void)
    * Initializes the RCC Oscillators according to the specified parameters
    * in the RCC_OscInitTypeDef structure.
    */
+#if defined(NUCLEO_F030R8_USE_HSI)
+  /* Use HSI when no external clock is connected, e.g. MB1136 C-01. */
+  /* HSI 8 MHz / 2 * 12 = 48 MHz. */
+  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
+  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
+  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
+  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
+  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
+  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
+#else
   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
   RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
   RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
   RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL6;
+#endif
   RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV1;
   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
     Error_Handler();