diff --git a/include/osg/GLDefines b/include/osg/GLDefines
index bebce6656..5a8f21958 100644
--- a/include/osg/GLDefines
+++ b/include/osg/GLDefines
@@ -690,10 +690,6 @@ namespace osg
             #endif
         #endif
     #endif
-
-    #if defined(OSG_GLES1_FEATURES) || defined(OSG_GLES2_FEATURES)|| defined(OSG_GLES3_FEATURES)
-        typedef double GLclampd;
-    #endif
 }
 
 #endif
diff --git a/include/osg/GLExtensions b/include/osg/GLExtensions
index b15091839..deb691f29 100644
--- a/include/osg/GLExtensions
+++ b/include/osg/GLExtensions
@@ -557,7 +557,7 @@ class OSG_EXPORT GLExtensions : public osg::Referenced
         bool isSGIXMinMaxSupported;
         bool isLogicOpSupported;
 
-        void (GL_APIENTRY * glBlendColor) (GLclampf red , GLclampf green , GLclampf blue , GLclampf alpha);
+        void (GL_APIENTRY * glBlendColor) (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
         void (GL_APIENTRY * glBlendEquation)(GLenum mode);
         void (GL_APIENTRY * glBlendEquationSeparate)(GLenum modeRGB, GLenum modeAlpha);
         void (GL_APIENTRY * glBlendEquationi)(GLuint buf,  GLenum mode);
@@ -599,7 +599,7 @@ class OSG_EXPORT GLExtensions : public osg::Referenced
         bool isMultisampleSupported;
         bool isMultisampleFilterHintSupported;
 
-        void (GL_APIENTRY * glSampleCoverage) (GLclampf value, GLboolean invert);
+        void (GL_APIENTRY * glSampleCoverage) (GLfloat value, GLboolean invert);
 
 
         // Point
@@ -725,8 +725,9 @@ class OSG_EXPORT GLExtensions : public osg::Referenced
         void (GL_APIENTRY * glScissorArrayv) (GLuint first, GLsizei count, const GLint * v);
         void (GL_APIENTRY * glScissorIndexed) (GLuint index, GLint left, GLint bottom, GLsizei width, GLsizei height);
         void (GL_APIENTRY * glScissorIndexedv) (GLuint index, const GLint * v);
-        void (GL_APIENTRY * glDepthRangeArrayv) (GLuint first, GLsizei count, const GLclampd * v);
-        void (GL_APIENTRY * glDepthRangeIndexed) (GLuint index, GLclampd n, GLclampd f);
+        void (GL_APIENTRY * glDepthRangeArrayv) (GLuint first, GLsizei count, const GLdouble * v);
+        void (GL_APIENTRY * glDepthRangeIndexed) (GLuint index, GLdouble n, GLdouble f);
+        void (GL_APIENTRY * glDepthRangeIndexedf) (GLuint index, GLfloat n, GLfloat f);
         void (GL_APIENTRY * glGetFloati_v) (GLenum target, GLuint index, GLfloat *data);
         void (GL_APIENTRY * glGetDoublei_v) (GLenum target, GLuint index, GLdouble *data);
 
diff --git a/src/osg/DepthRangeIndexed.cpp b/src/osg/DepthRangeIndexed.cpp
index 5ae846931..9aaedb3cf 100644
--- a/src/osg/DepthRangeIndexed.cpp
+++ b/src/osg/DepthRangeIndexed.cpp
@@ -41,7 +41,11 @@ void DepthRangeIndexed::apply(State& state) const
     const GLExtensions* extensions = state.get<GLExtensions>();
     if (extensions->glDepthRangeIndexed)
     {
-        extensions->glDepthRangeIndexed(static_cast<GLuint>(_index), static_cast<GLclampd>(_zNear), static_cast<GLclampd>(_zFar));
+        extensions->glDepthRangeIndexed(static_cast<GLuint>(_index), static_cast<GLdouble>(_zNear), static_cast<GLdouble>(_zFar));
+    }
+    else if (extensions->glDepthRangeIndexedf)
+    {
+        extensions->glDepthRangeIndexedf(static_cast<GLuint>(_index), static_cast<GLfloat>(_zNear), static_cast<GLfloat>(_zFar));
     }
     else
     {
diff --git a/src/osg/GLExtensions.cpp b/src/osg/GLExtensions.cpp
index d89e63907..b5c2664d0 100644
--- a/src/osg/GLExtensions.cpp
+++ b/src/osg/GLExtensions.cpp
@@ -1171,6 +1171,7 @@ GLExtensions::GLExtensions(unsigned int in_contextID):
     osg::setGLExtensionFuncPtr(glScissorIndexedv, "glScissorIndexedv", validContext);
     osg::setGLExtensionFuncPtr(glDepthRangeArrayv, "glDepthRangeArrayv", validContext);
     osg::setGLExtensionFuncPtr(glDepthRangeIndexed, "glDepthRangeIndexed", validContext);
+    osg::setGLExtensionFuncPtr(glDepthRangeIndexedf, "glDepthRangeIndexedfOES", "glDepthRangeIndexedfNV", validContext);
     osg::setGLExtensionFuncPtr(glGetFloati_v, "glGetFloati_v", validContext);
     osg::setGLExtensionFuncPtr(glGetDoublei_v, "glGetDoublei_v", validContext);
     osg::setGLExtensionFuncPtr(glGetIntegerIndexedvEXT, "glGetIntegerIndexedvEXT", validContext);