diff --git a/src/appleseed/renderer/kernel/shading/closures.cpp b/src/appleseed/renderer/kernel/shading/closures.cpp
index 2b46250608..8f0a64d0d7 100644
--- a/src/appleseed/renderer/kernel/shading/closures.cpp
+++ b/src/appleseed/renderer/kernel/shading/closures.cpp
@@ -181,11 +181,9 @@ void CompositeClosure::process_closure_tree(
                     AshikminBRDFInputValues values;
 
                     linear_rgb_reflectance_to_spectrum(Color3f(p->Cd), values.m_rd);
-                    values.m_rd_alpha.set(1.0f);
                     values.m_rd_multiplier = p->kd;
 
                     linear_rgb_reflectance_to_spectrum(Color3f(p->Cs), values.m_rg);
-                    values.m_rg_alpha.set(1.0f);
                     values.m_rg_multiplier = p->ks;
                     values.m_fr_multiplier = 1.0;
                     values.m_nu = p->nu;
@@ -231,7 +229,6 @@ void CompositeClosure::process_closure_tree(
 
                     LambertianBRDFInputValues values;
                     values.m_reflectance.set(1.0f);
-                    values.m_reflectance_alpha.set(1.0f);
                     values.m_reflectance_multiplier = 1.0;
 
                     add_closure<LambertianBRDFInputValues>(
@@ -252,7 +249,6 @@ void CompositeClosure::process_closure_tree(
 
                     MicrofacetBRDFInputValues values;
                     values.m_reflectance.set(1.0f);
-                    values.m_reflectance_alpha.set(1.0f);
                     values.m_reflectance_multiplier = 1.0;
                     values.m_glossiness = p->glossiness;
                     values.m_glossiness_multiplier = 1.0;
@@ -273,7 +269,6 @@ void CompositeClosure::process_closure_tree(
 
                     OrenNayarBRDFInputValues values;
                     values.m_reflectance.set(1.0f);
-                    values.m_reflectance_alpha.set(1.0f);
                     values.m_reflectance_multiplier = 1.0;
                     values.m_roughness = p->roughness;
 
@@ -292,7 +287,6 @@ void CompositeClosure::process_closure_tree(
 
                     SpecularBRDFInputValues values;
                     values.m_reflectance.set(1.0f);
-                    values.m_reflectance_alpha.set(1.0f);
                     values.m_reflectance_multiplier = 1.0;
 
                     add_closure<SpecularBRDFInputValues>(
@@ -312,7 +306,6 @@ void CompositeClosure::process_closure_tree(
                     values.m_reflectance.set(1.0f);
                     values.m_from_ior = p->from_ior;
                     values.m_to_ior = p->to_ior;
-                    values.m_reflectance_alpha = Alpha(1.0);
                     values.m_reflectance_multiplier = 1.0;
 
                     add_closure<SpecularBTDFInputValues>(
@@ -330,7 +323,6 @@ void CompositeClosure::process_closure_tree(
 
                     DiffuseBTDFInputValues values;
                     values.m_transmittance.set(1.0f);
-                    values.m_transmittance_alpha = Alpha(1.0);
                     values.m_transmittance_multiplier = 1.0;
 
                     add_closure<DiffuseBTDFInputValues>(
diff --git a/src/appleseed/renderer/modeling/bsdf/orennayarbrdf.h b/src/appleseed/renderer/modeling/bsdf/orennayarbrdf.h
index ace28c0cd1..fd1e643575 100644
--- a/src/appleseed/renderer/modeling/bsdf/orennayarbrdf.h
+++ b/src/appleseed/renderer/modeling/bsdf/orennayarbrdf.h
@@ -56,7 +56,6 @@ namespace renderer
 DECLARE_INPUT_VALUES(OrenNayarBRDFInputValues)
 {
     Spectrum    m_reflectance;              // diffuse reflectance (albedo, technically)
-    Alpha       m_reflectance_alpha;        // unused
     double      m_reflectance_multiplier;
     double      m_roughness;
 };