diff --git a/firmware/util/timer.cpp b/firmware/util/timer.cpp
index b30ab89..77be3d2 100644
--- a/firmware/util/timer.cpp
+++ b/firmware/util/timer.cpp
@@ -54,6 +54,8 @@ bool Timer::hasElapsedMs(float milliseconds) const {
 	return hasElapsedUs(milliseconds * 1000);
 }
 
+static const float usPerTick = 1000000.0 / CH_CFG_ST_FREQUENCY;
+
 bool Timer::hasElapsedUs(float microseconds) const {
 	auto delta = getTimestamp() - m_lastReset;
 
@@ -64,10 +66,9 @@ bool Timer::hasElapsedUs(float microseconds) const {
 
 	auto delta32 = (uint32_t)delta;
 
-	return delta32 > TIME_US2I(microseconds);
+	return delta32 > (microseconds / usPerTick);
 }
 
-
 float Timer::getElapsedSeconds() const {
 	return getElapsedSeconds(getTimestamp());
 }
@@ -96,7 +97,7 @@ float Timer::getElapsedUs(int64_t stamp) const {
 
 	auto delta32 = (uint32_t)deltaNt;
 
-	return TIME_I2US(delta32);
+	return delta32 * usPerTick;
 }
 
 float Timer::getElapsedSecondsAndReset() {