diff --git a/src/materials/coatedglossy.cc b/src/materials/coatedglossy.cc
index 24f5adbb..45af0cdd 100644
--- a/src/materials/coatedglossy.cc
+++ b/src/materials/coatedglossy.cc
@@ -188,12 +188,13 @@ float coatedGlossyMat_t::OrenNayar(const vector3d_t &wi, const vector3d_t &wo, c
         double sigma_squared = textureSigma * textureSigma;
         double mOrenNayar_TextureA = 1.0 - 0.5 * (sigma_squared / (sigma_squared + 0.33));
         double mOrenNayar_TextureB = 0.45 * sigma_squared / (sigma_squared + 0.09);     
-        return mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta)));
     }
     else
     {
-        return orenA + orenB * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (orenA + orenB * maxcos_f * sin_alpha * tan_beta)));
     }
+
 }
 
 color_t coatedGlossyMat_t::eval(const renderState_t &state, const surfacePoint_t &sp, const vector3d_t &wo, const vector3d_t &wi, BSDF_t bsdfs, bool force_eval)const
diff --git a/src/materials/glossy.cc b/src/materials/glossy.cc
index ba6f4f62..d834524d 100644
--- a/src/materials/glossy.cc
+++ b/src/materials/glossy.cc
@@ -157,11 +157,11 @@ float glossyMat_t::OrenNayar(const vector3d_t &wi, const vector3d_t &wo, const v
         double sigma_squared = textureSigma * textureSigma;
         double mOrenNayar_TextureA = 1.0 - 0.5 * (sigma_squared / (sigma_squared + 0.33));
         double mOrenNayar_TextureB = 0.45 * sigma_squared / (sigma_squared + 0.09);     
-        return mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta)));
     }
     else
     {
-        return orenA + orenB * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (orenA + orenB * maxcos_f * sin_alpha * tan_beta)));
     }
 }
 
diff --git a/src/materials/glossy2.cc b/src/materials/glossy2.cc
index ba6f4f62..d834524d 100644
--- a/src/materials/glossy2.cc
+++ b/src/materials/glossy2.cc
@@ -157,11 +157,11 @@ float glossyMat_t::OrenNayar(const vector3d_t &wi, const vector3d_t &wo, const v
         double sigma_squared = textureSigma * textureSigma;
         double mOrenNayar_TextureA = 1.0 - 0.5 * (sigma_squared / (sigma_squared + 0.33));
         double mOrenNayar_TextureB = 0.45 * sigma_squared / (sigma_squared + 0.09);     
-        return mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta)));
     }
     else
     {
-        return orenA + orenB * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (orenA + orenB * maxcos_f * sin_alpha * tan_beta)));
     }
 }
 
diff --git a/src/materials/shinydiffuse.cc b/src/materials/shinydiffuse.cc
index 3a203a5a..0f480e59 100644
--- a/src/materials/shinydiffuse.cc
+++ b/src/materials/shinydiffuse.cc
@@ -215,14 +215,12 @@ CFLOAT shinyDiffuseMat_t::OrenNayar(const vector3d_t &wi, const vector3d_t &wo,
         double sigma_squared = textureSigma * textureSigma;
         double mOrenNayar_TextureA = 1.0 - 0.5 * (sigma_squared / (sigma_squared + 0.33));
         double mOrenNayar_TextureB = 0.45 * sigma_squared / (sigma_squared + 0.09);
-        
-        return mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (mOrenNayar_TextureA + mOrenNayar_TextureB * maxcos_f * sin_alpha * tan_beta)));
     }
     else
     {
-        return mOrenNayar_A + mOrenNayar_B * maxcos_f * sin_alpha * tan_beta;
+        return std::min(1.f, std::max(0.f, (float) (mOrenNayar_A + mOrenNayar_B * maxcos_f * sin_alpha * tan_beta)));
     }
-    
 }