diff --git a/src/test/Makefile b/src/test/Makefile
index 8e376ea51b..5001c57230 100644
--- a/src/test/Makefile
+++ b/src/test/Makefile
@@ -149,6 +149,7 @@ flight_imu_unittest : \
 	$(OBJECT_DIR)/flight/imu.o \
 	$(OBJECT_DIR)/flight/altitudehold.o \
 	$(OBJECT_DIR)/flight_imu_unittest.o \
+	$(OBJECT_DIR)/common/maths.o \
 	$(OBJECT_DIR)/gtest_main.a
 
 	$(CXX) $(CXX_FLAGS) -lpthread $^ -o $(OBJECT_DIR)/$@
diff --git a/src/test/unit/flight_imu_unittest.cc b/src/test/unit/flight_imu_unittest.cc
index 67425aa63d..44aada0687 100644
--- a/src/test/unit/flight_imu_unittest.cc
+++ b/src/test/unit/flight_imu_unittest.cc
@@ -85,18 +85,8 @@ void updateAccelerationReadings(rollAndPitchTrims_t *rollAndPitchTrims)
     UNUSED(rollAndPitchTrims);
 }
 
-int32_t applyDeadband(int32_t, int32_t) { return 0; }
-
 uint32_t micros(void) { return 0; }
 bool isBaroCalibrationComplete(void) { return true; }
 void performBaroCalibrationCycle(void) {}
 int32_t baroCalculateAltitude(void) { return 0; }
-int constrain(int amt, int low, int high)
-{
-    UNUSED(amt);
-    UNUSED(low);
-    UNUSED(high);
-    return 0;
-}
-
 }