diff --git a/core_generator/build.rs b/core_generator/build.rs
index 72c015c..cd2bf15 100644
--- a/core_generator/build.rs
+++ b/core_generator/build.rs
@@ -42,8 +42,8 @@ fn generate_config_module() -> Result<(), io::Error> {
     let path = src_path().join("config.rs");
     let mut f = File::create(&path)?;
 
-    let clock = env!("AVR_CPU_FREQUENCY");
-    writeln!(f, "pub const CPU_FREQUENCY: u32 = {};", clock)?;
+    let clock = env!("AVR_CPU_FREQUENCY_HZ");
+    writeln!(f, "pub const CPU_FREQUENCY_HZ: u32 = {};", clock)?;
     Ok(())
 }
 
diff --git a/src/modules/spi/clock.rs b/src/modules/spi/clock.rs
index aea8ff0..92fe90c 100644
--- a/src/modules/spi/clock.rs
+++ b/src/modules/spi/clock.rs
@@ -19,17 +19,17 @@ pub struct ClockMask(pub u8);
 impl ClockMask {
     /// Gets the clock mask for a specific baute rate.
     pub fn with_clock(spi_clock: u32) -> ClockMask {
-        let mut divider_bits = if spi_clock >= config::CPU_FREQUENCY / 2 {
+        let mut divider_bits = if spi_clock >= config::CPU_FREQUENCY_HZ / 2 {
             0
-        } else if spi_clock >= config::CPU_FREQUENCY / 4 {
+        } else if spi_clock >= config::CPU_FREQUENCY_HZ / 4 {
             1
-        } else if spi_clock >= config::CPU_FREQUENCY / 8 {
+        } else if spi_clock >= config::CPU_FREQUENCY_HZ / 8 {
             2
-        } else if spi_clock >= config::CPU_FREQUENCY / 16 {
+        } else if spi_clock >= config::CPU_FREQUENCY_HZ / 16 {
             3
-        } else if spi_clock >= config::CPU_FREQUENCY / 32 {
+        } else if spi_clock >= config::CPU_FREQUENCY_HZ / 32 {
             4
-        } else if spi_clock >= config::CPU_FREQUENCY / 64 {
+        } else if spi_clock >= config::CPU_FREQUENCY_HZ / 64 {
             5
         } else {
             6