diff --git a/src/Core/OpenGL/CShader.cpp b/src/Core/OpenGL/CShader.cpp
index 6f80732c..5f21794e 100644
--- a/src/Core/OpenGL/CShader.cpp
+++ b/src/Core/OpenGL/CShader.cpp
@@ -160,22 +160,22 @@ bool CShader::LinkShaders()
     return true;
 }
 
-bool CShader::IsValidProgram()
+bool CShader::IsValidProgram() const
 {
     return mProgramExists;
 }
 
-GLuint CShader::GetProgramID()
+GLuint CShader::GetProgramID() const
 {
     return mProgram;
 }
 
-GLuint CShader::GetUniformLocation(const char* pkUniform)
+GLuint CShader::GetUniformLocation(const char* pkUniform) const
 {
     return glGetUniformLocation(mProgram, pkUniform);
 }
 
-GLuint CShader::GetUniformBlockIndex(const char* pkUniformBlock)
+GLuint CShader::GetUniformBlockIndex(const char* pkUniformBlock) const
 {
     return glGetUniformBlockIndex(mProgram, pkUniformBlock);
 }
diff --git a/src/Core/OpenGL/CShader.h b/src/Core/OpenGL/CShader.h
index 6716c392..516390b1 100644
--- a/src/Core/OpenGL/CShader.h
+++ b/src/Core/OpenGL/CShader.h
@@ -35,10 +35,10 @@ public:
     bool CompileVertexSource(const char* pkSource);
     bool CompilePixelSource(const char* pkSource);
     bool LinkShaders();
-    bool IsValidProgram();
-    GLuint GetProgramID();
-    GLuint GetUniformLocation(const char* pkUniform);
-    GLuint GetUniformBlockIndex(const char* pkUniformBlock);
+    bool IsValidProgram() const;
+    GLuint GetProgramID() const;
+    GLuint GetUniformLocation(const char* pkUniform) const;
+    GLuint GetUniformBlockIndex(const char* pkUniformBlock) const;
     void UniformBlockBinding(GLuint BlockIndex, GLuint BlockBinding);
     void SetTextureUniforms(uint32 NumTextures);
     void SetNumLights(uint32 NumLights);