diff --git a/flight/Libraries/CoordinateConversions.c b/flight/Libraries/CoordinateConversions.c
index e3f3850f3..98b2aef80 100644
--- a/flight/Libraries/CoordinateConversions.c
+++ b/flight/Libraries/CoordinateConversions.c
@@ -31,7 +31,7 @@
 #include <stdint.h>
 #include "CoordinateConversions.h"
 
-#define F_PI 3.14159265358979323846f
+#define F_PI ((float)M_PI)
 #define RAD2DEG (180.0f/ F_PI)
 #define DEG2RAD (F_PI /180.0f)
 
diff --git a/flight/Libraries/math/sin_lookup.c b/flight/Libraries/math/sin_lookup.c
index 4b7fa7a8d..2d67ca162 100644
--- a/flight/Libraries/math/sin_lookup.c
+++ b/flight/Libraries/math/sin_lookup.c
@@ -33,6 +33,7 @@
 #include "stdbool.h"
 #include "stdint.h"
 
+#define F_PI ((float)M_PI)
 #define FLASH_TABLE
 #ifdef FLASH_TABLE
  /** Version of the code which precomputes the lookup table in flash **/
@@ -81,7 +82,7 @@ int sin_lookup_initalize()
 		return -1;
 
 	for(uint32_t i = 0; i < 180; i++)
-		sin_table[i] = sinf((float)i * 2 * ((float)M_PI) / 360.0f);
+		sin_table[i] = sinf((float)i * 2 * F_PI / 360.0f);
 
 	return 0;
 }
@@ -126,7 +127,7 @@ float cos_lookup_deg(float angle)
  */
 float sin_lookup_rad(float angle)
 {
-	int degrees = angle * 180.0f / ((float)M_PI);
+	int degrees = angle * 180.0f / F_PI;
 	return sin_lookup_deg(degrees);
 }
 
@@ -137,6 +138,6 @@ float sin_lookup_rad(float angle)
  */
 float cos_lookup_rad(float angle)
 {
-	int degrees = angle * 180.0f / ((float)M_PI);
+	int degrees = angle * 180.0f / F_PI;
 	return cos_lookup_deg(degrees);
 }
diff --git a/flight/Modules/Attitude/attitude.c b/flight/Modules/Attitude/attitude.c
index 81b351737..7a669dd2c 100644
--- a/flight/Modules/Attitude/attitude.c
+++ b/flight/Modules/Attitude/attitude.c
@@ -67,6 +67,8 @@
 #define UPDATE_RATE  25.0f
 #define GYRO_NEUTRAL 1665
 
+#define F_PI ((float)M_PI)
+
 #define PI_MOD(x) (fmod(x + M_PI, M_PI * 2) - M_PI)
 // Private types
 
@@ -513,10 +515,10 @@ static void updateAttitude(AccelsData * accelsData, GyrosData * gyrosData)
 		// Work out time derivative from INSAlgo writeup
 		// Also accounts for the fact that gyros are in deg/s
 		float qdot[4];
-		qdot[0] = (-q[1] * gyros[0] - q[2] * gyros[1] - q[3] * gyros[2]) * dT * (((float)M_PI) / 180 / 2);
-		qdot[1] = (q[0] * gyros[0] - q[3] * gyros[1] + q[2] * gyros[2]) * dT * (((float)M_PI) / 180 / 2);
-		qdot[2] = (q[3] * gyros[0] + q[0] * gyros[1] - q[1] * gyros[2]) * dT * (((float)M_PI) / 180 / 2);
-		qdot[3] = (-q[2] * gyros[0] + q[1] * gyros[1] + q[0] * gyros[2]) * dT * (((float)M_PI) / 180 / 2);
+		qdot[0] = (-q[1] * gyros[0] - q[2] * gyros[1] - q[3] * gyros[2]) * dT * (F_PI / 180.0f / 2.0f);
+		qdot[1] = (q[0] * gyros[0] - q[3] * gyros[1] + q[2] * gyros[2]) * dT * (F_PI / 180.0f / 2.0f);
+		qdot[2] = (q[3] * gyros[0] + q[0] * gyros[1] - q[1] * gyros[2]) * dT * (F_PI / 180.0f / 2.0f);
+		qdot[3] = (-q[2] * gyros[0] + q[1] * gyros[1] + q[0] * gyros[2]) * dT * (F_PI / 180.0f / 2.0f);
 		
 		// Take a time step
 		q[0] = q[0] + qdot[0];