diff --git a/wfobj-view.cc b/wfobj-view.cc
index b730df1..ec70dae 100644
--- a/wfobj-view.cc
+++ b/wfobj-view.cc
@@ -341,11 +341,11 @@ void Viewer::renderMaterial(const WFObj::Material & m)
     if (m.flags & WFObj::Material::SHININESS_BIT)
         glUniform1f(m_shininess_loc, m.shininess);
     if (m.flags & WFObj::Material::AMBIENT_BIT)
-        glUniform4fv(m_ambient_loc, 4, &m.ambient[0]);
+        glUniform4fv(m_ambient_loc, 1, &m.ambient[0]);
     if (m.flags & WFObj::Material::DIFFUSE_BIT)
-        glUniform4fv(m_diffuse_loc, 4, &m.diffuse[0]);
+        glUniform4fv(m_diffuse_loc, 1, &m.diffuse[0]);
     if (m.flags & WFObj::Material::SPECULAR_BIT)
-        glUniform4fv(m_specular_loc, 4, &m.specular[0]);
+        glUniform4fv(m_specular_loc, 1, &m.specular[0]);
     if (m.flags & WFObj::Material::TEXTURE_BIT)
     {
         cerr << "error: textured materials not implemented yet" << endl;