diff --git a/configure b/configure
index 5b15d122c07..00f31ce99a9 100755
--- a/configure
+++ b/configure
@@ -19379,3 +19379,15 @@ echo "$as_me: error: $ac_sub_configure failed for $ac_dir" >&2;}
   done
 fi
 
+echo ""
+echo ""
+echo "################################################################################"
+echo "################################################################################"
+echo "The LLVM project has deprecated building with configure & make."
+echo "The autoconf-based makefile build system will be removed in the 3.9 release."
+echo ""
+echo "Please migrate to the CMake-based build system."
+echo "For more information see: http://llvm.org/docs/CMake.html"
+echo "################################################################################"
+echo "################################################################################"
+
diff --git a/docs/BuildingLLVMWithAutotools.rst b/docs/BuildingLLVMWithAutotools.rst
index 6f9a1341055..083ead67ebb 100644
--- a/docs/BuildingLLVMWithAutotools.rst
+++ b/docs/BuildingLLVMWithAutotools.rst
@@ -5,6 +5,12 @@ Building LLVM With Autotools
 .. contents::
    :local:
 
+.. warning::
+
+    Building LLVM with autoconf is deprecated as of 3.8. The autoconf build
+    system will be removed in 3.9. Please migrate to using CMake. For more
+    information see: `Building LLVM with CMake <CMake.html>`_
+
 Overview
 ========
 
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index 44f5823bca3..ba7e436fb0e 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -37,6 +37,10 @@ Non-comprehensive list of changes in this release
   Windows 7. Earlier versions, including Windows Vista and XP are no longer
   supported.
 
+* With this release, the autoconf build system is deprecated. It will be removed
+  in the 3.9 release. Please migrate to using CMake. For more information see:
+  `Building LLVM with CMake <CMake.html>`_
+
 .. NOTE
    For small 1-3 sentence descriptions, just add an entry at the end of
    this list. If your description won't fit comfortably in one bullet