diff --git a/code/qcommon/q_math.c b/code/qcommon/q_math.c
index d2e0187d..979989ba 100644
--- a/code/qcommon/q_math.c
+++ b/code/qcommon/q_math.c
@@ -787,10 +787,12 @@ vec_t VectorNormalize( vec3_t v ) {
 	float	length, ilength;
 
 	length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
-	length = sqrt (length);
 
 	if ( length ) {
-		ilength = 1/length;
+		/* writing it this way allows gcc to recognize that rsqrt can be used */
+		ilength = 1/(float)sqrt (length);
+		/* sqrt(length) = length * (1 / sqrt(length)) */
+		length *= ilength;
 		v[0] *= ilength;
 		v[1] *= ilength;
 		v[2] *= ilength;
@@ -803,11 +805,13 @@ vec_t VectorNormalize2( const vec3_t v, vec3_t out) {
 	float	length, ilength;
 
 	length = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
-	length = sqrt (length);
 
 	if (length)
 	{
-		ilength = 1/length;
+		/* writing it this way allows gcc to recognize that rsqrt can be used */
+		ilength = 1/(float)sqrt (length);
+		/* sqrt(length) = length * (1 / sqrt(length)) */
+		length *= ilength;
 		out[0] = v[0]*ilength;
 		out[1] = v[1]*ilength;
 		out[2] = v[2]*ilength;