diff --git a/docs/config_options.md b/docs/config_options.md
index d728a49c3..afc29fae9 100644
--- a/docs/config_options.md
+++ b/docs/config_options.md
@@ -91,6 +91,8 @@ This is a C header file that is one of the first things included, and will persi
   * key combination that allows the use of magic commands (useful for debugging)
 * `#define USB_MAX_POWER_CONSUMPTION`
   * sets the maximum power (in mA) over USB for the device (default: 500)
+* `#define SCL_CLOCK 100000L`
+  * sets the SCL_CLOCK speed for split keyboards. The default is `100000L` but some boards can be set to `400000L`.
 
 ## Features That Can Be Disabled
 
diff --git a/quantum/split_common/i2c.h b/quantum/split_common/i2c.h
index b4c72bde0..b3cbe8c82 100644
--- a/quantum/split_common/i2c.h
+++ b/quantum/split_common/i2c.h
@@ -25,7 +25,9 @@
 #define SLAVE_BUFFER_SIZE 0x20
 
 // i2c SCL clock frequency
-#define SCL_CLOCK  400000L
+#ifndef SCL_CLOCK
+#define SCL_CLOCK  100000L
+#endif
 
 // Support 8bits right now (8 cols) will need to edit to take higher (code exists in delta split?)
 extern volatile uint8_t i2c_slave_buffer[SLAVE_BUFFER_SIZE];