diff --git a/pkgs/development/compilers/llvm/3.3/llvm.nix b/pkgs/development/compilers/llvm/3.3/llvm.nix
index e40014a960c..d0f8fcb3bf8 100644
--- a/pkgs/development/compilers/llvm/3.3/llvm.nix
+++ b/pkgs/development/compilers/llvm/3.3/llvm.nix
@@ -22,11 +22,20 @@ in stdenv.mkDerivation rec {
 
   cmakeFlags = with stdenv; [
     "-DCMAKE_BUILD_TYPE=Release"
+    "-DLLVM_BUILD_TESTS=ON"
     "-DLLVM_ENABLE_FFI=ON"
     "-DLLVM_BINUTILS_INCDIR=${binutils}/include"
     "-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=R600" # for mesa
   ] ++ stdenv.lib.optional (!isDarwin) "-DBUILD_SHARED_LIBS=ON";
 
+  postBuild = ''
+    paxmark m bin/{lli,llvm-rtdyld}
+
+    paxmark m unittests/ExecutionEngine/JIT/JITTests
+    paxmark m unittests/ExecutionEngine/MCJIT/MCJITTests
+    paxmark m unittests/Support/SupportTests
+  '';
+
   enableParallelBuilding = true;
 
   doCheck = true;
diff --git a/pkgs/development/compilers/llvm/3.4/llvm.nix b/pkgs/development/compilers/llvm/3.4/llvm.nix
index fad11b7a123..c24188b4846 100644
--- a/pkgs/development/compilers/llvm/3.4/llvm.nix
+++ b/pkgs/development/compilers/llvm/3.4/llvm.nix
@@ -35,15 +35,25 @@ in stdenv.mkDerivation rec {
     mkdir -p $out/
     ln -sv $PWD/lib $out
   '';
-  postBuild = "rm -fR $out";
 
   cmakeFlags = with stdenv; [
     "-DCMAKE_BUILD_TYPE=Release"
+    "-DLLVM_BUILD_TESTS=ON"
     "-DLLVM_ENABLE_FFI=ON"
     "-DLLVM_BINUTILS_INCDIR=${binutils}/include"
     "-DCMAKE_CXX_FLAGS=-std=c++11"
   ] ++ stdenv.lib.optional (!isDarwin) "-DBUILD_SHARED_LIBS=ON";
 
+  postBuild = ''
+    rm -fR $out
+
+    paxmark m bin/{lli,llvm-rtdyld}
+
+    paxmark m unittests/ExecutionEngine/JIT/JITTests
+    paxmark m unittests/ExecutionEngine/MCJIT/MCJITTests
+    paxmark m unittests/Support/SupportTests
+  '';
+
   enableParallelBuilding = true;
 
   passthru.src = src;