diff --git a/inc/math.h b/inc/math.h
index f6b7819..3313ead 100644
--- a/inc/math.h
+++ b/inc/math.h
@@ -34,7 +34,7 @@
 static inline float round(float x)
 {
 #ifdef ARM_MATH_CM7
-	register float rv;
+	float rv;
 	__asm volatile ("vrinta.f32 %0, %1" : "=w" (rv) : "w" (x));
 	return rv;
 #else
@@ -47,7 +47,7 @@
 static inline float floor(float x)
 {
 #ifdef ARM_MATH_CM7
-	register float rv;
+	float rv;
 	__asm volatile ("vrintm.f32 %0, %1" : "=w" (rv) : "w" (x));
 	return rv;
 #else
@@ -59,7 +59,7 @@
 static inline float trunc(float x)
 {
 #ifdef ARM_MATH_CM7
-	register float rv;
+	float rv;
 	__asm volatile ("vrintz.f32 %0, %1" : "=w" (rv) : "w" (x));
 	return rv;
 #else
@@ -71,7 +71,7 @@
 static inline float ceil(float x)
 {
 #ifdef ARM_MATH_CM7
-	register float rv;
+	float rv;
 	__asm volatile ("vrintp.f32 %0, %1" : "=w" (rv) : "w" (x));
 	return rv;
 #else
@@ -87,7 +87,7 @@
 #if defined ARM_MATH_CM7 || defined ARM_MATH_CM4
 	if (x >= 0)
 	{
-		register float rv;
+		float rv;
 		__asm volatile ("vsqrt.f32 %0, %1" : "=w" (rv) : "w" (x));
 		return rv;
 	}
@@ -124,7 +124,7 @@
 static inline float fabs(float x)
 {
 #if defined(ARM_MATH_CM7) || defined(ARM_MATH_CM4)
-	register float rv;
+	float rv;
 	__asm volatile ("vabs.f32 %0, %1" : "=w" (rv) : "w" (x));
 	return rv;
 #else
@@ -136,7 +136,7 @@
 static inline float fmax(float a, float b)
 {
 #ifdef ARM_MATH_CM7
-	register float v;
+	float v;
 	__asm volatile ("vmaxnm.f32 %0, %1, %2" : "=w" (v) : "w" (a), "w" (b));         //max instruction
 	return v;
 #else
@@ -148,7 +148,7 @@
 static inline float fmin(float a, float b)
 {
 #ifdef ARM_MATH_CM7
-	register float v;
+	float v;
 	__asm volatile ("vminnm.f32 %0, %1, %2" : "=w" (v) : "w" (a), "w" (b));         //min instruction
 	return v;
 #else