diff --git a/pkgs/development/tools/misc/ycmd/2-ycm-cmake.patch b/pkgs/development/tools/misc/ycmd/2-ycm-cmake.patch
deleted file mode 100644
index baa907b2126..00000000000
--- a/pkgs/development/tools/misc/ycmd/2-ycm-cmake.patch
+++ /dev/null
@@ -1,37 +0,0 @@
-diff --git a/cpp/ycm/CMakeLists.txt b/cpp/ycm/CMakeLists.txt
-index 2074c58e..9ecd6e57 100644
---- a/cpp/ycm/CMakeLists.txt
-+++ b/cpp/ycm/CMakeLists.txt
-@@ -335,7 +335,7 @@
-       COMMAND ${CMAKE_COMMAND} -E copy "${LIBCLANG_TARGET}" "$<TARGET_FILE_DIR:${PROJECT_NAME}>"
-     )
- 
--    if( APPLE )
-+  #if( APPLE )
-       # In OS X El Capitan, Apple introduced System Integrity Protection.
-       # Amongst other things, this introduces features to the dynamic loader
-       # (dyld) which cause it to "sanitise" (and complain about) embedded
-@@ -354,15 +354,15 @@
-       # simply strip the rpath entry from the dylib.  There's no way any
-       # @executable_path that python might have could be in any way useful to
-       # libclang.dylib, so this seems perfectly safe.
--      get_filename_component( LIBCLANG_TAIL ${LIBCLANG_TARGET} NAME )
--      add_custom_command( TARGET ${PROJECT_NAME}
--                          POST_BUILD
--                          COMMAND install_name_tool
--                          "-delete_rpath"
--                          "@executable_path/../lib"
--                          "$<TARGET_FILE_DIR:${PROJECT_NAME}>/${LIBCLANG_TAIL}"
--                        )
--    endif()
-+      #    get_filename_component( LIBCLANG_TAIL ${LIBCLANG_TARGET} NAME )
-+      #add_custom_command( TARGET ${PROJECT_NAME}
-+      #                    POST_BUILD
-+      #                    COMMAND install_name_tool
-+      #                    "-delete_rpath"
-+      #                    "@executable_path/../lib"
-+      #                    "$<TARGET_FILE_DIR:${PROJECT_NAME}>/${LIBCLANG_TAIL}"
-+      #                  )
-+      # endif()
-   endif()
- endif()
diff --git a/pkgs/development/tools/misc/ycmd/default.nix b/pkgs/development/tools/misc/ycmd/default.nix
index 9ac227ac006..eb02d0e79dd 100644
--- a/pkgs/development/tools/misc/ycmd/default.nix
+++ b/pkgs/development/tools/misc/ycmd/default.nix
@@ -7,12 +7,12 @@
 
 stdenv.mkDerivation rec {
   name = "ycmd-${version}";
-  version = "2017-02-03";
+  version = "2017-03-27";
 
   src = fetchgit {
     url = "git://github.com/Valloric/ycmd.git";
-    rev = "ec7a154f8fe50c071ecd0ac6841de8a50ce92f5d";
-    sha256 = "0rzxgqqqmmrv9r4k2ji074iprhw6sb0jkvh84wvi45yfyphsh0xi";
+    rev = "2ef1ae0d00a06a47fed3aacfd465a310e8bdb0d2";
+    sha256 = "0p5knlxgy66zi229ns1lfdhz5lram93vahmmk54w98fr3h8b1yfj";
   };
 
   buildInputs = [ cmake boost ]  ++ stdenv.lib.optional stdenv.isDarwin Cocoa;
@@ -22,7 +22,7 @@ stdenv.mkDerivation rec {
     ${python.interpreter} build.py --clang-completer --system-boost
   '';
 
-  patches = [ ./2-ycm-cmake.patch ];
+  patches = [ ./dont-symlink-clang.patch ];
 
   configurePhase = ":";
 
diff --git a/pkgs/development/tools/misc/ycmd/dont-symlink-clang.patch b/pkgs/development/tools/misc/ycmd/dont-symlink-clang.patch
new file mode 100644
index 00000000000..6af691426bb
--- /dev/null
+++ b/pkgs/development/tools/misc/ycmd/dont-symlink-clang.patch
@@ -0,0 +1,16 @@
+diff --git a/cpp/ycm/CMakeLists.txt b/cpp/ycm/CMakeLists.txt
+index 00e4882..8f29797 100644
+--- a/cpp/ycm/CMakeLists.txt
++++ b/cpp/ycm/CMakeLists.txt
+@@ -310,11 +310,6 @@ if ( EXTERNAL_LIBCLANG_PATH OR USE_SYSTEM_LIBCLANG )
+       # our libraries require, in particular the Python one (from pyenv for
+       # instance).
+       set( CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE )
+-      # When loading our library, the dynamic linker will look for
+-      # libclang.so.4, not libclang.so.4.x.
+-      file( RENAME
+-            ${EXTERNAL_LIBCLANG_PATH}.${CLANG_MAJOR_VERSION}.${CLANG_MINOR_VERSION}
+-            ${EXTERNAL_LIBCLANG_PATH}.${CLANG_MAJOR_VERSION} )
+     endif()
+   endif()
+ 
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 7970732ce3f..b650d4f5af1 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -6992,7 +6992,7 @@ with pkgs;
 
   ycmd = callPackage ../development/tools/misc/ycmd {
     inherit (darwin.apple_sdk.frameworks) Cocoa;
-    llvmPackages = llvmPackages_39;
+    llvmPackages = llvmPackages_4;
     python = python2;
   };