diff --git a/src/common/shadervars.h b/src/common/shadervars.h
index 2ab61a2..80c7ae7 100644
--- a/src/common/shadervars.h
+++ b/src/common/shadervars.h
@@ -165,18 +165,16 @@
           dataSize(0),
           layout(BLOCKLAYOUT_PACKED),
           isRowMajorLayout(false),
-          staticUse(false),
-          registerIndex(-1)
+          staticUse(false)
     {}
 
-    InterfaceBlock(const char *name, unsigned int arraySize, unsigned int registerIndex)
+    InterfaceBlock(const char *name, unsigned int arraySize)
         : name(name),
           arraySize(arraySize),
           dataSize(0),
           layout(BLOCKLAYOUT_SHARED),
           isRowMajorLayout(false),
-          staticUse(false),
-          registerIndex(registerIndex)
+          staticUse(false)
     {}
 
     std::string name;
@@ -188,9 +186,6 @@
     bool staticUse;
     std::vector<InterfaceBlockField> fields;
     std::vector<BlockMemberInfo> blockInfo;
-
-    // HLSL-specific members
-    unsigned int registerIndex;
 };
 
 }
diff --git a/src/compiler/translator/UniformHLSL.cpp b/src/compiler/translator/UniformHLSL.cpp
index fbb0b0a..8116202 100644
--- a/src/compiler/translator/UniformHLSL.cpp
+++ b/src/compiler/translator/UniformHLSL.cpp
@@ -225,7 +225,9 @@
         const TFieldList &fieldList = interfaceBlock.fields();
 
         unsigned int arraySize = static_cast<unsigned int>(interfaceBlock.arraySize());
-        InterfaceBlock activeBlock(interfaceBlock.name().c_str(), arraySize, mInterfaceBlockRegister);
+        unsigned int activeRegister = mInterfaceBlockRegister;
+
+        InterfaceBlock activeBlock(interfaceBlock.name().c_str(), arraySize);
         for (unsigned int typeIndex = 0; typeIndex < fieldList.size(); typeIndex++)
         {
             const TField &field = *fieldList[typeIndex];
@@ -236,7 +238,7 @@
             traverser.traverse(*field.type(), fullFieldName);
         }
 
-        mInterfaceBlockRegisterMap[activeBlock.name] = mInterfaceBlockRegister;
+        mInterfaceBlockRegisterMap[activeBlock.name] = activeRegister;
         mInterfaceBlockRegister += std::max(1u, arraySize);
 
         BlockLayoutType blockLayoutType = GetBlockLayoutType(interfaceBlock.blockStorage());
@@ -258,12 +260,12 @@
         {
             for (unsigned int arrayIndex = 0; arrayIndex < arraySize; arrayIndex++)
             {
-                interfaceBlocks += interfaceBlockString(interfaceBlock, activeBlock.registerIndex + arrayIndex, arrayIndex);
+                interfaceBlocks += interfaceBlockString(interfaceBlock, activeRegister + arrayIndex, arrayIndex);
             }
         }
         else
         {
-            interfaceBlocks += interfaceBlockString(interfaceBlock, activeBlock.registerIndex, GL_INVALID_INDEX);
+            interfaceBlocks += interfaceBlockString(interfaceBlock, activeRegister, GL_INVALID_INDEX);
         }
     }
 
diff --git a/src/libGLESv2/ProgramBinary.cpp b/src/libGLESv2/ProgramBinary.cpp
index 5a22500..f56ece5 100644
--- a/src/libGLESv2/ProgramBinary.cpp
+++ b/src/libGLESv2/ProgramBinary.cpp
@@ -1631,7 +1631,7 @@
         mUniforms.push_back(new LinkedUniform(GL_FLOAT, GL_HIGH_FLOAT, "gl_DepthRange.diff", 0, -1, sh::BlockMemberInfo::getDefaultBlockInfo()));
     }
 
-    if (!linkUniformBlocks(infoLog, vertexShader->getInterfaceBlocks(), fragmentShader->getInterfaceBlocks()))
+    if (!linkUniformBlocks(infoLog, *vertexShader, *fragmentShader))
     {
         success = false;
     }
@@ -2151,9 +2151,12 @@
     return true;
 }
 
-bool ProgramBinary::linkUniformBlocks(InfoLog &infoLog, const std::vector<sh::InterfaceBlock> &vertexInterfaceBlocks,
-                                      const std::vector<sh::InterfaceBlock> &fragmentInterfaceBlocks)
+bool ProgramBinary::linkUniformBlocks(InfoLog &infoLog, const VertexShader &vertexShader,
+                                      const FragmentShader &fragmentShader)
 {
+    const std::vector<sh::InterfaceBlock> &vertexInterfaceBlocks = vertexShader.getInterfaceBlocks();
+    const std::vector<sh::InterfaceBlock> &fragmentInterfaceBlocks = fragmentShader.getInterfaceBlocks();
+
     // Check that interface blocks defined in the vertex and fragment shaders are identical
     typedef std::map<std::string, const sh::InterfaceBlock*> UniformBlockMap;
     UniformBlockMap linkedUniformBlocks;
@@ -2180,7 +2183,7 @@
 
     for (unsigned int blockIndex = 0; blockIndex < vertexInterfaceBlocks.size(); blockIndex++)
     {
-        if (!defineUniformBlock(infoLog, GL_VERTEX_SHADER, vertexInterfaceBlocks[blockIndex]))
+        if (!defineUniformBlock(infoLog, vertexShader, vertexInterfaceBlocks[blockIndex]))
         {
             return false;
         }
@@ -2188,7 +2191,7 @@
 
     for (unsigned int blockIndex = 0; blockIndex < fragmentInterfaceBlocks.size(); blockIndex++)
     {
-        if (!defineUniformBlock(infoLog, GL_FRAGMENT_SHADER, fragmentInterfaceBlocks[blockIndex]))
+        if (!defineUniformBlock(infoLog, fragmentShader, fragmentInterfaceBlocks[blockIndex]))
         {
             return false;
         }
@@ -2290,7 +2293,7 @@
     }
 }
 
-bool ProgramBinary::defineUniformBlock(InfoLog &infoLog, GLenum shader, const sh::InterfaceBlock &interfaceBlock)
+bool ProgramBinary::defineUniformBlock(InfoLog &infoLog, const Shader &shader, const sh::InterfaceBlock &interfaceBlock)
 {
     // create uniform block entries if they do not exist
     if (getUniformBlockIndex(interfaceBlock.name) == GL_INVALID_INDEX)
@@ -2326,12 +2329,15 @@
     ASSERT(blockIndex != GL_INVALID_INDEX);
     ASSERT(blockIndex + elementCount <= mUniformBlocks.size());
 
+    unsigned int interfaceBlockRegister = shader.getInterfaceBlockRegister(interfaceBlock.name);
+
     for (unsigned int uniformBlockElement = 0; uniformBlockElement < elementCount; uniformBlockElement++)
     {
         UniformBlock *uniformBlock = mUniformBlocks[blockIndex + uniformBlockElement];
         ASSERT(uniformBlock->name == interfaceBlock.name);
 
-        if (!assignUniformBlockRegister(infoLog, uniformBlock, shader, interfaceBlock.registerIndex + uniformBlockElement))
+        if (!assignUniformBlockRegister(infoLog, uniformBlock, shader.getType(),
+                                        interfaceBlockRegister + uniformBlockElement))
         {
             return false;
         }
diff --git a/src/libGLESv2/ProgramBinary.h b/src/libGLESv2/ProgramBinary.h
index c73ce66..161afa1 100644
--- a/src/libGLESv2/ProgramBinary.h
+++ b/src/libGLESv2/ProgramBinary.h
@@ -194,13 +194,13 @@
     bool linkUniforms(InfoLog &infoLog, const std::vector<sh::Uniform> &vertexUniforms, const std::vector<sh::Uniform> &fragmentUniforms);
     bool defineUniform(GLenum shader, const sh::Uniform &constant, InfoLog &infoLog);
     bool areMatchingInterfaceBlocks(InfoLog &infoLog, const sh::InterfaceBlock &vertexInterfaceBlock, const sh::InterfaceBlock &fragmentInterfaceBlock);
-    bool linkUniformBlocks(InfoLog &infoLog, const std::vector<sh::InterfaceBlock> &vertexUniformBlocks, const std::vector<sh::InterfaceBlock> &fragmentUniformBlocks);
+    bool linkUniformBlocks(InfoLog &infoLog, const VertexShader &vertexShader, const FragmentShader &fragmentShader);
     bool gatherTransformFeedbackLinkedVaryings(InfoLog &infoLog, const std::vector<LinkedVarying> &linkedVaryings,
                                                const std::vector<std::string> &transformFeedbackVaryingNames,
                                                GLenum transformFeedbackBufferMode,
                                                std::vector<LinkedVarying> *outTransformFeedbackLinkedVaryings) const;
     void defineUniformBlockMembers(const std::vector<sh::InterfaceBlockField> &fields, const std::string &prefix, int blockIndex, BlockInfoItr *blockInfoItr, std::vector<unsigned int> *blockUniformIndexes);
-    bool defineUniformBlock(InfoLog &infoLog, GLenum shader, const sh::InterfaceBlock &interfaceBlock);
+    bool defineUniformBlock(InfoLog &infoLog, const Shader &shader, const sh::InterfaceBlock &interfaceBlock);
     bool assignUniformBlockRegister(InfoLog &infoLog, UniformBlock *uniformBlock, GLenum shader, unsigned int registerIndex);
     void defineOutputVariables(FragmentShader *fragmentShader);
     void initializeUniformStorage();
diff --git a/src/libGLESv2/Shader.cpp b/src/libGLESv2/Shader.cpp
index b3c09fe..ea5a8d1 100644
--- a/src/libGLESv2/Shader.cpp
+++ b/src/libGLESv2/Shader.cpp
@@ -115,6 +115,12 @@
     getSourceImpl(mHlsl, bufSize, length, buffer);
 }
 
+unsigned int Shader::getInterfaceBlockRegister(const std::string &blockName) const
+{
+    ASSERT(mInterfaceBlockRegisterMap.count(blockName) > 0);
+    return mInterfaceBlockRegisterMap.find(blockName)->second;
+}
+
 const std::vector<sh::Uniform> &Shader::getUniforms() const
 {
     return mActiveUniforms;
@@ -370,6 +376,18 @@
         void *activeInterfaceBlocks;
         ShGetInfoPointer(compiler, SH_ACTIVE_INTERFACE_BLOCKS_ARRAY, &activeInterfaceBlocks);
         mActiveInterfaceBlocks = *(std::vector<sh::InterfaceBlock>*)activeInterfaceBlocks;
+
+        for (size_t blockIndex = 0; blockIndex < mActiveInterfaceBlocks.size(); blockIndex++)
+        {
+            const sh::InterfaceBlock &interfaceBlock = mActiveInterfaceBlocks[blockIndex];
+
+            unsigned int index = -1;
+            bool result = ShGetInterfaceBlockRegister(compiler, interfaceBlock.name.c_str(), &index);
+            UNUSED_ASSERTION_VARIABLE(result);
+            ASSERT(result);
+
+            mInterfaceBlockRegisterMap[interfaceBlock.name] = index;
+        }
     }
     else
     {
@@ -440,7 +458,7 @@
 {
 }
 
-GLenum VertexShader::getType()
+GLenum VertexShader::getType() const
 {
     return GL_VERTEX_SHADER;
 }
@@ -503,7 +521,7 @@
 {
 }
 
-GLenum FragmentShader::getType()
+GLenum FragmentShader::getType() const
 {
     return GL_FRAGMENT_SHADER;
 }
diff --git a/src/libGLESv2/Shader.h b/src/libGLESv2/Shader.h
index 6b41bb7..95cedba 100644
--- a/src/libGLESv2/Shader.h
+++ b/src/libGLESv2/Shader.h
@@ -57,7 +57,7 @@
 
     virtual ~Shader();
 
-    virtual GLenum getType() = 0;
+    virtual GLenum getType() const = 0;
     GLuint getHandle() const;
 
     void deleteSource();
@@ -87,6 +87,7 @@
 
     static void releaseCompiler();
     static ShShaderOutput getCompilerOutputType(GLenum shader);
+    unsigned int getInterfaceBlockRegister(const std::string &blockName) const;
 
     bool usesDepthRange() const { return mUsesDepthRange; }
     bool usesPointSize() const { return mUsesPointSize; }
@@ -135,6 +136,7 @@
     std::string mInfoLog;
     std::vector<sh::Uniform> mActiveUniforms;
     std::vector<sh::InterfaceBlock> mActiveInterfaceBlocks;
+    std::map<std::string, unsigned int> mInterfaceBlockRegisterMap;
 
     ResourceManager *mResourceManager;
 };
@@ -148,7 +150,7 @@
 
     ~VertexShader();
 
-    virtual GLenum getType();
+    virtual GLenum getType() const;
     virtual void compile();
     virtual void uncompile();
     int getSemanticIndex(const std::string &attributeName);
@@ -170,7 +172,7 @@
 
     ~FragmentShader();
 
-    virtual GLenum getType();
+    virtual GLenum getType() const;
     virtual void compile();
     virtual void uncompile();
     const std::vector<sh::Attribute> &getOutputVariables() const;