diff --git a/f_shader.glsl b/f_shader.glsl
index e1fdafb..a26bf41 100644
--- a/f_shader.glsl
+++ b/f_shader.glsl
@@ -1,7 +1,9 @@
 
+uniform vec4 ambient, diffuse, specular;
+uniform float shininess;
+
 varying vec3 eye_pos_i;
 varying vec3 normal_i;
-varying vec4 diffuse_i;
 
 void main(void)
 {
@@ -10,7 +12,7 @@ void main(void)
     float NdotL, RdotEye;
 
     lightDir = vec3(-0.1, 0, -0.9);
-    color = vec4(0.2, 0.2, 0.2, 1.0);  /* ambient light */
+    color = ambient;  /* ambient light */
     n = normalize(normal_i);
 
     NdotL = max(dot(n, -lightDir), 0.0);
@@ -18,12 +20,12 @@ void main(void)
     if (NdotL > 0.0)
     {
         /* diffuse component */
-        color += diffuse_i * NdotL;
+        color += diffuse * NdotL;
         /* specular component */
         RdotEye = dot(normalize(eye_pos_i), normalize(reflect(-lightDir, n)));
         if (RdotEye > 0.0)
         {
-            color += pow(RdotEye, 96.5);
+            color += specular * pow(RdotEye, shininess);
         }
     }
 
diff --git a/v_shader.glsl b/v_shader.glsl
index 4881a17..efb7e85 100644
--- a/v_shader.glsl
+++ b/v_shader.glsl
@@ -1,16 +1,13 @@
 
 attribute vec3 pos;
-attribute vec3 color;
 attribute vec3 normal;
 
 varying vec3 eye_pos_i;
 varying vec3 normal_i;
-varying vec4 diffuse_i;
 
 void main(void)
 {
     gl_Position = gl_ModelViewProjectionMatrix * vec4(pos, 1);
     eye_pos_i = vec3(gl_Position.x, gl_Position.y, gl_Position.z);
     normal_i = gl_NormalMatrix * normal;
-    diffuse_i = vec4(color, 1);
 }
diff --git a/wfobj-view.cc b/wfobj-view.cc
index 59df81e..0bebee6 100644
--- a/wfobj-view.cc
+++ b/wfobj-view.cc
@@ -40,6 +40,7 @@ private:
     bool m_dragging;
     float m_dist;
     GLuint m_program, m_vs, m_fs;
+    GLint m_ambient_loc, m_diffuse_loc, m_specular_loc, m_shininess_loc;
 };
 
 char * loadFile(const char *fname)
@@ -193,6 +194,23 @@ Viewer::Viewer(const char * filename)
         exit(1);
     }
 
+    m_ambient_loc = glGetUniformLocation(m_program, "ambient");
+    m_diffuse_loc = glGetUniformLocation(m_program, "diffuse");
+    m_specular_loc = glGetUniformLocation(m_program, "specular");
+    m_shininess_loc = glGetUniformLocation(m_program, "shininess");
+    if (m_ambient_loc < 0 || m_diffuse_loc < 0 || m_specular_loc < 0
+            || m_shininess_loc < 0)
+    {
+        cerr << "glGetUniformLocation() returned < 0" << endl;
+        exit(1);
+    }
+
+    glUseProgram(m_program);
+    glUniform4f(m_ambient_loc, 0.2, 0.2, 0.2, 1.0);
+    glUniform4f(m_diffuse_loc, 1.0, 1.0, 1.0, 1.0);
+    glUniform4f(m_specular_loc, 1.0, 1.0, 1.0, 1.0);
+    glUniform1f(m_shininess_loc, 85.0);
+
     /* Print out the object's size */
     const float * aabb = m_obj.getAABB();
     cout << "Object width:  " << (aabb[3]-aabb[0]) << endl;
@@ -321,13 +339,13 @@ void Viewer::run()
 void Viewer::renderMaterial(const WFObj::Material & m)
 {
     if (m.flags & WFObj::Material::SHININESS_BIT)
-        glMaterialf(GL_FRONT, GL_SHININESS, m.shininess);
+        glUniform1f(m_shininess_loc, m.shininess);
     if (m.flags & WFObj::Material::AMBIENT_BIT)
-        glMaterialfv(GL_FRONT, GL_AMBIENT, &m.ambient[0]);
+        glUniform4fv(m_ambient_loc, 4, &m.ambient[0]);
     if (m.flags & WFObj::Material::DIFFUSE_BIT)
-        glMaterialfv(GL_FRONT, GL_DIFFUSE, &m.diffuse[0]);
+        glUniform4fv(m_diffuse_loc, 4, &m.ambient[0]);
     if (m.flags & WFObj::Material::SPECULAR_BIT)
-        glMaterialfv(GL_FRONT, GL_SPECULAR, &m.specular[0]);
+        glUniform4fv(m_specular_loc, 4, &m.ambient[0]);
     if (m.flags & WFObj::Material::TEXTURE_BIT)
     {
         cerr << "error: textured materials not implemented yet" << endl;