diff --git a/PlatformIO.md b/PlatformIO.md
index f8ae72a8..f46f4d25 100644
--- a/PlatformIO.md
+++ b/PlatformIO.md
@@ -159,6 +159,7 @@ Below is a table with supported clocks. Defaults to 16 MHz if not specified.
 | 14.7456 MHz | External   | `14745600L`               |
 | 12 MHz      | External   | `12000000L`               |
 | 11.0592 MHz | External   | `11059200L`               |
+| 9.216 MHz   | External   | `9216000L`                |
 | 8 MHz       | External   | `8000000L`                |
 | 7.3728  MHz | External   | `7372800L`                |
 | 6 MHz       | External   | `6000000L`                |
@@ -255,6 +256,7 @@ Suggested baud rates for a particular clock speed are in **bold text**.
 | `14745600L` |         |        |  X     |        |  X     |  **X** |  X     |  X     |  X    |  X     |
 | `12000000L` |         |  X     |        |  X     |        |        |  **X** |        |  X    |  X     |
 | `11059200L` |         |        |  X     |        |  X     |  X     |  **X** |  X     |  X    |  X     |
+| `9216000L`  |         |        |        |        |  X     |  **X** |  X     |  X     |  X    |  X     |
 | `8000000L`  |  X      |  X     |        |  X     |        |  X     |  X     |  **X** |  X    |  X     |
 | `7372800L`  |         |        |  X     |        |  X     |  **X** |  X     |  X     |  X    |  X     |
 | `6000000L`  |         |        |        |  X     |        |        |  **X** |  X     |  X    |  X     |
diff --git a/README.md b/README.md
index d67b0fad..1d4968a2 100644
--- a/README.md
+++ b/README.md
@@ -65,6 +65,7 @@ Make sure you connect an ISP programmer, and select the correct one in the "Prog
 | 14.7456 MHz | External crystal/oscillator | Great clock for UART communication with no error              |
 | 12 MHz      | External crystal/oscillator |                                                               |
 | 11.0592 MHz | External crystal/oscillator | Great clock for UART communication with no error              |
+| 9.216 MHz   | External crystal/oscillator | Great clock for UART communication with no error              |
 | 8 MHz       | External crystal/oscillator | Common clock when working with 3.3V                           |
 | 7.3728 MHz  | External crystal/oscillator | Great clock for UART communication with no error              |
 | 6 MHz       | External crystal/oscillator |                                                               |
diff --git a/avr/boards.txt b/avr/boards.txt
index 23ffc0aa..9ba34949 100644
--- a/avr/boards.txt
+++ b/avr/boards.txt
@@ -165,6 +165,12 @@ menu.baudrate=Baud rate
 328.menu.clock.11_0592MHz_external.build.clkpr=
 328.menu.clock.11_0592MHz_external.build.f_cpu=11059200L
 
+328.menu.clock.9_216MHz_external=External 9.216 MHz
+328.menu.clock.9_216MHz_external.upload.default_speed=115200
+328.menu.clock.9_216MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
+328.menu.clock.9_216MHz_external.build.clkpr=
+328.menu.clock.9_216MHz_external.build.f_cpu=9216000L
+
 328.menu.clock.8MHz_external=External 8 MHz
 328.menu.clock.8MHz_external.upload.default_speed=57600
 328.menu.clock.8MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
@@ -379,6 +385,12 @@ menu.baudrate=Baud rate
 168.menu.clock.11_0592MHz_external.build.clkpr=
 168.menu.clock.11_0592MHz_external.build.f_cpu=11059200L
 
+168.menu.clock.9_216MHz_external=External 9.216 MHz
+168.menu.clock.9_216MHz_external.upload.default_speed=115200
+168.menu.clock.9_216MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
+168.menu.clock.9_216MHz_external.build.clkpr=
+168.menu.clock.9_216MHz_external.build.f_cpu=9216000L
+
 168.menu.clock.8MHz_external=External 8 MHz
 168.menu.clock.8MHz_external.upload.default_speed=57600
 168.menu.clock.8MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
@@ -592,6 +604,12 @@ menu.baudrate=Baud rate
 88.menu.clock.11_0592MHz_external.build.clkpr=
 88.menu.clock.11_0592MHz_external.build.f_cpu=11059200L
 
+88.menu.clock.9_216MHz_external=External 9.216 MHz
+88.menu.clock.9_216MHz_external.upload.default_speed=115200
+88.menu.clock.9_216MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
+88.menu.clock.9_216MHz_external.build.clkpr=
+88.menu.clock.9_216MHz_external.build.f_cpu=9216000L
+
 88.menu.clock.8MHz_external=External 8 MHz
 88.menu.clock.8MHz_external.upload.default_speed=57600
 88.menu.clock.8MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
@@ -805,6 +823,12 @@ menu.baudrate=Baud rate
 48.menu.clock.11_0592MHz_external.build.clkpr=
 48.menu.clock.11_0592MHz_external.build.f_cpu=11059200L
 
+48.menu.clock.9_216MHz_external=External 9.216 MHz
+48.menu.clock.9_216MHz_external.upload.default_speed=115200
+48.menu.clock.9_216MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
+48.menu.clock.9_216MHz_external.build.clkpr=
+48.menu.clock.9_216MHz_external.build.f_cpu=9216000L
+
 48.menu.clock.8MHz_external=External 8 MHz
 48.menu.clock.8MHz_external.upload.default_speed=57600
 48.menu.clock.8MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
@@ -1002,6 +1026,12 @@ menu.baudrate=Baud rate
 8.menu.clock.11_0592MHz_external.bootloader.ckopt_bit=0
 8.menu.clock.11_0592MHz_external.build.f_cpu=11059200L
 
+8.menu.clock.9_216MHz_external=External 9.216 MHz
+8.menu.clock.9_216MHz_external.upload.default_speed=115200
+8.menu.clock.9_216MHz_external.bootloader.low_fuses=0b1111{bootloader.cksel_bits}
+8.menu.clock.9_216MHz_external.build.clkpr=
+8.menu.clock.9_216MHz_external.build.f_cpu=9216000L
+
 8.menu.clock.8MHz_external=External 8 MHz
 8.menu.clock.8MHz_external.upload.default_speed=57600
 8.menu.clock.8MHz_external.bootloader.sut_cksel_bits=111111