diff --git a/HLSL/FastNoiseLite.hlsl b/HLSL/FastNoiseLite.hlsl
index 4934774..0da5ccd 100644
--- a/HLSL/FastNoiseLite.hlsl
+++ b/HLSL/FastNoiseLite.hlsl
@@ -95,6 +95,15 @@ typedef int fnl_cellular_return_type;
 #define FNL_DOMAIN_WARP_BASICGRID 2
 typedef int fnl_domain_warp_type;
 
+// Removes [0x80004005 - unknown error] 'internal error: no storage type for block output' 
+#if UNITY_VERSION
+    #define FNL_FLATTEN [flatten]
+    #define FNL_UNROLL [unroll(1)]
+#else
+    #define FNL_FLATTEN
+    #define FNL_UNROLL
+#endif
+
 /**
  * Structure containing entire noise system state.
  * @note Must only be created using fnlCreateState(optional: seed). To ensure defaults are set.
@@ -537,7 +546,7 @@ static float _fnlSingleValue3D(int seed, FNLfloat x, FNLfloat y, FNLfloat z);
 
 static float _fnlGenNoiseSingle2D(fnl_state state, int seed, FNLfloat x, FNLfloat y)
 {
-    switch (state.noise_type)
+    FNL_FLATTEN switch (state.noise_type)
     {
     case FNL_NOISE_OPENSIMPLEX2:
         return _fnlSingleSimplex2D(seed, x, y);
@@ -558,7 +567,7 @@ static float _fnlGenNoiseSingle2D(fnl_state state, int seed, FNLfloat x, FNLfloa
 
 static float _fnlGenNoiseSingle3D(fnl_state state, int seed, FNLfloat x, FNLfloat y, FNLfloat z)
 {
-    switch (state.noise_type)
+    FNL_FLATTEN switch (state.noise_type)
     {
     case FNL_NOISE_OPENSIMPLEX2:
         return _fnlSingleOpenSimplex23D(seed, x, y, z);
@@ -952,7 +961,7 @@ static float _fnlSingleOpenSimplex23D(int seed, FNLfloat x, FNLfloat y, FNLfloat
     float value = 0;
     float a = (0.6f - x0 * x0) - (y0 * y0 + z0 * z0);
 
-    for (int l = 0; ; l++)
+    FNL_UNROLL for (int l = 0; ; l++)
     {
         if (a > 0)
         {
@@ -1291,7 +1300,7 @@ static float _fnlSingleCellular2D(fnl_state state, int seed, FNLfloat x, FNLfloa
     int xPrimed = (xr - 1) * PRIME_X;
     int yPrimedBase = (yr - 1) * PRIME_Y;
 
-    switch (state.cellular_distance_func)
+    FNL_FLATTEN switch (state.cellular_distance_func)
     {
     default:
     case FNL_CELLULAR_DISTANCE_EUCLIDEAN:
@@ -1380,7 +1389,7 @@ static float _fnlSingleCellular2D(fnl_state state, int seed, FNLfloat x, FNLfloa
     }
     }
 
-    if (state.cellular_distance_func == FNL_CELLULAR_DISTANCE_EUCLIDEAN && state.cellular_return_type >= FNL_CELLULAR_RETURN_TYPE_DISTANCE)
+    FNL_FLATTEN if (state.cellular_distance_func == FNL_CELLULAR_DISTANCE_EUCLIDEAN && state.cellular_return_type >= FNL_CELLULAR_RETURN_TYPE_DISTANCE)
     {
         distance0 = _fnlFastSqrt(distance0);
         if (state.cellular_return_type >= FNL_CELLULAR_RETURN_TYPE_DISTANCE2)
@@ -1767,7 +1776,7 @@ static void _fnlSingleDomainWarpOpenSimplex2Gradient(int seed, float warpAmp, fl
 
 static void _fnlDoSingleDomainWarp2D(fnl_state state, int seed, float amp, float freq, FNLfloat x, FNLfloat y, inout FNLfloat xp, inout FNLfloat yp)
 {
-    switch (state.domain_warp_type)
+    FNL_FLATTEN switch (state.domain_warp_type)
     {
     case FNL_DOMAIN_WARP_OPENSIMPLEX2:
         _fnlSingleDomainWarpSimplexGradient(seed, amp * 38.283687591552734375f, freq, x, y, xp, yp, false);
@@ -1783,7 +1792,7 @@ static void _fnlDoSingleDomainWarp2D(fnl_state state, int seed, float amp, float
 
 static void _fnlDoSingleDomainWarp3D(fnl_state state, int seed, float amp, float freq, FNLfloat x, FNLfloat y, FNLfloat z, inout FNLfloat xp, inout FNLfloat yp, inout FNLfloat zp)
 {
-    switch (state.domain_warp_type)
+    FNL_FLATTEN switch (state.domain_warp_type)
     {
     case FNL_DOMAIN_WARP_OPENSIMPLEX2:
         _fnlSingleDomainWarpOpenSimplex2Gradient(seed, amp * 32.69428253173828125f, freq, x, y, z, xp, yp, zp, false);
@@ -2251,7 +2260,7 @@ float fnlGetNoise2D(fnl_state state, FNLfloat x, FNLfloat y)
 {
     _fnlTransformNoiseCoordinate2D(state, x, y);
 
-    switch (state.fractal_type)
+    FNL_FLATTEN switch (state.fractal_type)
     {
     default:
         return _fnlGenNoiseSingle2D(state, state.seed, x, y);
@@ -2269,7 +2278,7 @@ float fnlGetNoise3D(fnl_state state, FNLfloat x, FNLfloat y, FNLfloat z)
     _fnlTransformNoiseCoordinate3D(state, x, y, z);
 
     // Select a noise type
-    switch (state.fractal_type)
+    FNL_FLATTEN switch (state.fractal_type)
     {
     default:
         return _fnlGenNoiseSingle3D(state, state.seed, x, y, z);
@@ -2284,7 +2293,7 @@ float fnlGetNoise3D(fnl_state state, FNLfloat x, FNLfloat y, FNLfloat z)
 
 void fnlDomainWarp2D(fnl_state state, inout FNLfloat x, inout FNLfloat y)
 {
-    switch (state.fractal_type)
+    FNL_FLATTEN switch (state.fractal_type)
     {
     default:
         _fnlDomainWarpSingle2D(state, x, y);
@@ -2300,7 +2309,7 @@ void fnlDomainWarp2D(fnl_state state, inout FNLfloat x, inout FNLfloat y)
 
 void fnlDomainWarp3D(fnl_state state, inout FNLfloat x, inout FNLfloat y, inout FNLfloat z)
 {
-    switch (state.fractal_type)
+    FNL_FLATTEN switch (state.fractal_type)
     {
     default:
         _fnlDomainWarpSingle3D(state, x, y, z);
@@ -2312,4 +2321,4 @@ void fnlDomainWarp3D(fnl_state state, inout FNLfloat x, inout FNLfloat y, inout
         _fnlDomainWarpFractalIndependent3D(state, x, y, z);
         break;
     }
-}
+}
\ No newline at end of file