diff --git a/var/spack/packages/clang/package.py b/var/spack/packages/clang/package.py
index b0097bd1261c71ad01f83d00e6b784be83691c96..4f10385dbda396225986154f27b7944ddc3f1d86 100644
--- a/var/spack/packages/clang/package.py
+++ b/var/spack/packages/clang/package.py
@@ -29,11 +29,10 @@ class Clang(Package):
        Objective C and Objective C++ front-end for the LLVM compiler.
     """
     homepage = "http://clang.llvm.org"
-    url      = "http://llvm.org/releases/3.4.2/cfe-3.4.2.src.tar.gz"
+    list_url = "http://llvm.org/releases/download.html"
 
     depends_on("llvm")
-
-    version('3.4.2', '87945973b7c73038871c5f849a818588')
+    version('3.4.2', '87945973b7c73038871c5f849a818588', url='http://llvm.org/releases/3.4.2/cfe-3.4.2.src.tar.xz')
 
     def install(self, spec, prefix):
         env['CXXFLAGS'] = self.compiler.cxx11_flag
diff --git a/var/spack/packages/llvm/package.py b/var/spack/packages/llvm/package.py
index 69354a5c9095eaddc2f038ffc0dfd0d196beea92..9d2be690bb14463b523e7c5b5cf89291fc3a1ba3 100644
--- a/var/spack/packages/llvm/package.py
+++ b/var/spack/packages/llvm/package.py
@@ -32,15 +32,13 @@ class Llvm(Package):
        it is the full name of the project.
     """
     homepage = "http://llvm.org/"
-    url      = "http://llvm.org/releases/3.4.2/llvm-3.4.2.src.tar.gz"
+    list_url = "http://llvm.org/releases/download.html"
 
-    version('3.4.2', 'a20669f75967440de949ac3b1bad439c')
-    version('3.0', 'a8e5f5f1c1adebae7b4a654c376a6005',
-            url='http://llvm.org/releases/3.0/llvm-3.0.tar.gz')
-    version('2.9', '793138412d2af2c7c7f54615f8943771',
-            url='http://llvm.org/releases/2.9/llvm-2.9.tgz')
-    version('2.8', '220d361b4d17051ff4bb21c64abe05ba',
-            url='http://llvm.org/releases/2.8/llvm-2.8.tgz')
+    version('3.5.1', '2d3d8004f38852aa679e5945b8ce0b14', url='http://llvm.org/releases/3.5.1/llvm-3.5.1.src.tar.xz')
+    version('3.4.2', 'a20669f75967440de949ac3b1bad439c', url='http://llvm.org/releases/3.4.2/llvm-3.4.2.src.tar.gz')
+    version('3.0',   'a8e5f5f1c1adebae7b4a654c376a6005', url='http://llvm.org/releases/3.0/llvm-3.0.tar.gz')
+    version('2.9',   '793138412d2af2c7c7f54615f8943771', url='http://llvm.org/releases/2.9/llvm-2.9.tgz')
+    version('2.8',   '220d361b4d17051ff4bb21c64abe05ba', url='http://llvm.org/releases/2.8/llvm-2.8.tgz')
 
     def install(self, spec, prefix):
         env['CXXFLAGS'] = self.compiler.cxx11_flag