diff --git a/HandmadeMath.h b/HandmadeMath.h
index eb72c85..8db5f05 100644
--- a/HandmadeMath.h
+++ b/HandmadeMath.h
@@ -223,7 +223,6 @@ HMMDEF float HMM_ToRadians(float Degrees);
 HMMDEF float HMM_Inner(hmm_vec3 A, hmm_vec3 B);
 HMMDEF float HMM_SquareRoot(float Float);
 HMMDEF float HMM_LengthSquareRoot(hmm_vec3 A);
-HMMDEF float HMM_FastInverseSquareRoot(float Number);
 HMMDEF float HMM_Length(hmm_vec3 A);    
 HMMDEF float HMM_Power(float Base, int Exponent);
 HMMDEF float HMM_Clamp(float Min, float Value, float Max);
@@ -352,24 +351,6 @@ HMM_LengthSquareRoot(hmm_vec3 A)
     return (Result);
 }
 
-HINLINE float
-HMM_FastInverseSquareRoot(float Number)
-{
-    long i;
-    float x2, y;
-    const float threehalfs = 1.5f;
-
-    x2 = Number * 0.5f;
-    y  = Number;
-    i  = * ( long * ) &y;          // evil floating point bit level hacking
-    i  = 0x5f3759df - ( i >> 1 );  // what the fuck? 
-    y  = * ( float * ) &i;
-    
-    y  = y * ( threehalfs - ( x2 * y * y ) );
-
-    return ( y );
-}
-
 HINLINE float
 HMM_Length(hmm_vec3 A)
 {