diff --git a/arduino-hal/Cargo.toml b/arduino-hal/Cargo.toml
index 1f400c73f3..a3bf3693a4 100644
--- a/arduino-hal/Cargo.toml
+++ b/arduino-hal/Cargo.toml
@@ -19,6 +19,7 @@ critical-section-impl = ["avr-device/critical-section-impl"]
 board-selected = []
 mcu-atmega = []
 mcu-attiny = []
+internal-clock = []
 arduino-diecimila = ["mcu-atmega", "atmega-hal/atmega168", "board-selected"]
 arduino-leonardo = ["mcu-atmega", "atmega-hal/atmega32u4", "board-selected"]
 arduino-mega2560 = ["mcu-atmega", "atmega-hal/atmega2560", "board-selected"]
diff --git a/arduino-hal/src/clock.rs b/arduino-hal/src/clock.rs
index 7c53088015..efe191e002 100644
--- a/arduino-hal/src/clock.rs
+++ b/arduino-hal/src/clock.rs
@@ -14,19 +14,38 @@ pub(crate) mod default {
     ///
     /// However, you can of course still use other clock speeds but you'll then need to correctly
     /// name the types from the HAL crate using your own clock definition.
-    #[cfg(any(
-        feature = "arduino-diecimila",
-        feature = "arduino-leonardo",
-        feature = "arduino-mega2560",
-        feature = "arduino-mega1280",
-        feature = "arduino-nano",
-        feature = "arduino-uno",
-        feature = "sparkfun-promicro",
-        feature = "sparkfun-promini-5v",
-        feature = "trinket-pro",
-        feature = "nano168",
+    #[cfg(all(
+        any(
+            feature = "arduino-diecimila",
+            feature = "arduino-leonardo",
+            feature = "arduino-mega2560",
+            feature = "arduino-mega1280",
+            feature = "arduino-nano",
+            feature = "arduino-uno",
+            feature = "sparkfun-promicro",
+            feature = "sparkfun-promini-5v",
+            feature = "trinket-pro",
+            feature = "nano168",
+        ),
+        not(feature = "internal-clock")
     ))]
     pub type DefaultClock = avr_hal_generic::clock::MHz16;
+    #[cfg(all(
+        any(
+            feature = "arduino-diecimila",
+            feature = "arduino-leonardo",
+            feature = "arduino-mega2560",
+            feature = "arduino-mega1280",
+            feature = "arduino-nano",
+            feature = "arduino-uno",
+            feature = "sparkfun-promicro",
+            feature = "sparkfun-promini-5v",
+            feature = "trinket-pro",
+            feature = "nano168",
+        ),
+        feature = "internal-clock"
+    ))]
+    pub type DefaultClock = avr_hal_generic::clock::MHz8;
     #[cfg(any(feature = "trinket", feature = "sparkfun-promini-3v3"))]
     pub type DefaultClock = avr_hal_generic::clock::MHz8;
 }