diff --git a/src/stm32/stm32f0_i2c.c b/src/stm32/stm32f0_i2c.c
index df53aa29..4c68779d 100644
--- a/src/stm32/stm32f0_i2c.c
+++ b/src/stm32/stm32f0_i2c.c
@@ -15,14 +15,46 @@ struct i2c_info {
     uint8_t scl_pin, sda_pin, function;
 };
 
+#if CONFIG_MACH_STM32F0
+DECL_ENUMERATION("i2c_bus", "i2c1_PB6_PB7", 0);
+DECL_CONSTANT_STR("BUS_PINS_i2c1_PB6_PB7", "PB6,PB7");
+DECL_ENUMERATION("i2c_bus", "i2c1_PF1_PF0", 1);
+DECL_CONSTANT_STR("BUS_PINS_i2c1_PF1_PF0", "PF1,PF0");
+DECL_ENUMERATION("i2c_bus", "i2c1_PB8_PB9", 2);
+DECL_CONSTANT_STR("BUS_PINS_i2c1_PB8_PB9", "PB8,PB9");
+// Deprecated "i2c1a" style mappings
 DECL_ENUMERATION("i2c_bus", "i2c1", 0);
 DECL_CONSTANT_STR("BUS_PINS_i2c1", "PB6,PB7");
 DECL_ENUMERATION("i2c_bus", "i2c1a", 1);
 DECL_CONSTANT_STR("BUS_PINS_i2c1a", "PF1,PF0");
+#elif CONFIG_MACH_STM32G0
+DECL_ENUMERATION("i2c_bus", "i2c1_PB6_PB7", 0);
+DECL_CONSTANT_STR("BUS_PINS_i2c1_PB6_PB7", "PB6,PB7");
+DECL_ENUMERATION("i2c_bus", "i2c1_PB8_PB9", 1);
+DECL_CONSTANT_STR("BUS_PINS_i2c1_PB8_PB9", "PB8,PB9");
+DECL_ENUMERATION("i2c_bus", "i2c3_PB3_PB4", 2);
+DECL_CONSTANT_STR("BUS_PINS_i2c3_PB3_PB4", "PB3,PB4");
+DECL_ENUMERATION("i2c_bus", "i2c2_PB10_PB11", 3);
+DECL_CONSTANT_STR("BUS_PINS_i2c2_PB10_PB11", "PB10,PB11");
+DECL_ENUMERATION("i2c_bus", "i2c2_PB13_PB14", 4);
+DECL_CONSTANT_STR("BUS_PINS_i2c2_PB13_PB14", "PB13,PB14");
+DECL_ENUMERATION("i2c_bus", "i2c1_PA9_PA10", 5);
+DECL_CONSTANT_STR("BUS_PINS_i2c1_PA9_PA10", "PA9,PA10");
+#endif
 
 static const struct i2c_info i2c_bus[] = {
+#if CONFIG_MACH_STM32F0
     { I2C1, GPIO('B', 6), GPIO('B', 7), GPIO_FUNCTION(1) },
     { I2C1, GPIO('F', 1), GPIO('F', 0), GPIO_FUNCTION(1) },
+    { I2C1, GPIO('B', 8), GPIO('B', 9), GPIO_FUNCTION(1) },
+#elif CONFIG_MACH_STM32G0
+    { I2C1, GPIO('B', 6), GPIO('B', 7), GPIO_FUNCTION(6) },
+    { I2C1, GPIO('B', 8), GPIO('B', 9), GPIO_FUNCTION(6) },
+    { I2C3, GPIO('B', 3), GPIO('B', 4), GPIO_FUNCTION(6) },
+    { I2C2, GPIO('B', 10), GPIO('B', 11), GPIO_FUNCTION(6) },
+    { I2C2, GPIO('B', 13), GPIO('B', 14), GPIO_FUNCTION(6) },
+    { I2C1, GPIO('A', 9), GPIO('A', 10), GPIO_FUNCTION(6) },
+#endif
 };
 
 struct i2c_config
diff --git a/src/stm32/stm32g0.c b/src/stm32/stm32g0.c
index 1964d89f..c243743b 100644
--- a/src/stm32/stm32g0.c
+++ b/src/stm32/stm32g0.c
@@ -38,6 +38,8 @@ lookup_clock_line(uint32_t periph_base)
         return (struct cline){.en=&RCC->APBENR1,.rst=&RCC->APBRSTR1,.bit=1<<13};
     if (periph_base == CRS_BASE)
         return (struct cline){.en=&RCC->APBENR1,.rst=&RCC->APBRSTR1,.bit=1<<16};
+    if (periph_base == I2C3_BASE)
+        return (struct cline){.en=&RCC->APBENR1,.rst=&RCC->APBRSTR1,.bit=1<<23};
     if (periph_base == TIM1_BASE)
         return (struct cline){.en=&RCC->APBENR2,.rst=&RCC->APBRSTR2,.bit=1<<11};
     if (periph_base == SPI1_BASE)