diff --git a/autobuild.xml b/autobuild.xml
index 712b917b16..68126a2271 100644
--- a/autobuild.xml
+++ b/autobuild.xml
@@ -1005,65 +1005,17 @@
         <string>glext</string>
         <key>platforms</key>
         <map>
-          <key>darwin64</key>
+          <key>common</key>
           <map>
             <key>archive</key>
             <map>
               <key>hash</key>
-              <string>c5e9a59c7cf03c88a5cb4ab0a9c21091</string>
+              <string>3fe4e2f975a39ddd5719ce0b0ed677a0</string>
               <key>url</key>
-              <string>https://automated-builds-secondlife-com.s3.amazonaws.com/ct2/99835/880141/glext-68-darwin64-571812.tar.bz2</string>
+              <string>https://automated-builds-secondlife-com.s3.amazonaws.com/ct2/101462/892321/glext-68-common-572823.tar.bz2</string>
             </map>
             <key>name</key>
-            <string>darwin64</string>
-          </map>
-          <key>linux</key>
-          <map>
-            <key>archive</key>
-            <map>
-              <key>hash</key>
-              <string>baf1fd13e1fe6aef586200fc87a70f53</string>
-              <key>url</key>
-              <string>http://automated-builds-secondlife-com.s3.amazonaws.com/hg/repo/p64_3p-glext/rev/314200/arch/Linux/installer/glext-68-linux-314200.tar.bz2</string>
-            </map>
-            <key>name</key>
-            <string>linux</string>
-          </map>
-          <key>linux64</key>
-          <map>
-            <key>archive</key>
-            <map>
-              <key>hash</key>
-              <string>5f3c9d61b620f949b199ebd8885218ed</string>
-              <key>url</key>
-              <string>http://automated-builds-secondlife-com.s3.amazonaws.com/hg/repo/p64_3p-glext/rev/314200/arch/Linux/installer/glext-68-linux64-314200.tar.bz2</string>
-            </map>
-            <key>name</key>
-            <string>linux64</string>
-          </map>
-          <key>windows</key>
-          <map>
-            <key>archive</key>
-            <map>
-              <key>hash</key>
-              <string>6a311615bce59b01cf73ee65012a9b38</string>
-              <key>url</key>
-              <string>http://automated-builds-secondlife-com.s3.amazonaws.com/ct2/54951/511711/glext-68-windows-538965.tar.bz2</string>
-            </map>
-            <key>name</key>
-            <string>windows</string>
-          </map>
-          <key>windows64</key>
-          <map>
-            <key>archive</key>
-            <map>
-              <key>hash</key>
-              <string>daf619dab1cf7518af6532b18800c4b0</string>
-              <key>url</key>
-              <string>http://automated-builds-secondlife-com.s3.amazonaws.com/ct2/54924/511490/glext-68-windows64-538965.tar.bz2</string>
-            </map>
-            <key>name</key>
-            <string>windows64</string>
+            <string>common</string>
           </map>
         </map>
         <key>version</key>
diff --git a/indra/cmake/GLEXT.cmake b/indra/cmake/GLEXT.cmake
index 9fd3923bfd..a749644202 100644
--- a/indra/cmake/GLEXT.cmake
+++ b/indra/cmake/GLEXT.cmake
@@ -2,9 +2,7 @@
 include(Prebuilt)
 
 if (NOT USESYSTEMLIBS)
-  if (WINDOWS OR LINUX)
-    use_prebuilt_binary(glext)
-  endif (WINDOWS OR LINUX)
+  use_prebuilt_binary(glext)
   use_prebuilt_binary(glh_linear)
   set(GLEXT_INCLUDE_DIR ${LIBS_PREBUILT_DIR}/include)
 endif (NOT USESYSTEMLIBS)
diff --git a/indra/cmake/LLRender.cmake b/indra/cmake/LLRender.cmake
index 868922451f..2d9d3725ad 100644
--- a/indra/cmake/LLRender.cmake
+++ b/indra/cmake/LLRender.cmake
@@ -3,10 +3,12 @@
 include(Variables)
 include(FreeType)
 include(GLH)
+include(GLEXT)
 
 set(LLRENDER_INCLUDE_DIRS
     ${LIBS_OPEN_DIR}/llrender
     ${GLH_INCLUDE_DIR}
+    ${GLEXT_INCLUDE_DIR}
     )
 
 if (BUILD_HEADLESS)
diff --git a/indra/llrender/llglheaders.h b/indra/llrender/llglheaders.h
index c53631dc7b..154f1aa2bd 100644
--- a/indra/llrender/llglheaders.h
+++ b/indra/llrender/llglheaders.h
@@ -577,11 +577,13 @@ extern PFNGLUNIFORMBLOCKBINDINGPROC glUniformBlockBinding;
 //----------------------------------------------------------------------------
 // LL_DARWIN
 
+#define GL_GLEXT_LEGACY
 #include <OpenGL/gl.h>
 #include <OpenGL/glu.h>
 
 #define GL_EXT_separate_specular_color 1
-#include <OpenGL/glext.h>
+#define GL_GLEXT_PROTOTYPES
+#include "GL/glext.h"
 
 #include "GL/glh_extensions.h"
 
diff --git a/indra/llrender/llglslshader.cpp b/indra/llrender/llglslshader.cpp
index 0212c605c3..67f82c9c5e 100644
--- a/indra/llrender/llglslshader.cpp
+++ b/indra/llrender/llglslshader.cpp
@@ -452,7 +452,7 @@ BOOL LLGLSLShader::createShader(std::vector<LLStaticHashedString> * attributes,
 #ifdef GL_INTERLEAVED_ATTRIBS
     if (varying_count > 0 && varyings)
     {
-        glTransformFeedbackVaryings(mProgramObject, varying_count, varyings, GL_INTERLEAVED_ATTRIBS);
+        glTransformFeedbackVaryings((GLuint64) mProgramObject, varying_count, varyings, GL_INTERLEAVED_ATTRIBS);
     }
 #endif