diff --git a/pkgs/development/compilers/llvm/4/llvm.nix b/pkgs/development/compilers/llvm/4/llvm.nix
index 0559a7aee23..1fe79d9300a 100644
--- a/pkgs/development/compilers/llvm/4/llvm.nix
+++ b/pkgs/development/compilers/llvm/4/llvm.nix
@@ -24,6 +24,11 @@
 let
   src = fetch "llvm" "0l9bf7kdwhlj0kq1hawpyxhna1062z3h7qcz2y8nfl9dz2qksy6s";
 
+  aarch64Patch = fetchpatch {
+    url = https://reviews.llvm.org/file/data/2oqw5rhhklsapbjrhlpd/PHID-FILE-lvo4fcs6hjvkxb5wneg2/D40423.diff;
+    sha256 = "0b0h7n7lxw33pn2j061hm9050zn263gmiig937g5cmcvjimxlybb";
+  };
+
   # Used when creating a version-suffixed symlink of libLLVM.dylib
   shortVersion = with stdenv.lib;
     concatStringsSep "." (take 2 (splitString "." release_version));
@@ -81,6 +86,8 @@ in stdenv.mkDerivation rec {
       substituteInPlace lib/esan/esan_sideline_linux.cpp \
         --replace 'struct sigaltstack' 'stack_t'
     )
+  '' + stdenv.lib.optionalString stdenv.isAarch64 ''
+    patch -p0 < ${aarch64Patch}
   '';
 
   # hacky fix: created binaries need to be run before installation
diff --git a/pkgs/development/compilers/llvm/5/llvm.nix b/pkgs/development/compilers/llvm/5/llvm.nix
index 520e42c3360..20b0f4b20c6 100644
--- a/pkgs/development/compilers/llvm/5/llvm.nix
+++ b/pkgs/development/compilers/llvm/5/llvm.nix
@@ -24,6 +24,11 @@
 let
   src = fetch "llvm" "1nin64vz21hyng6jr19knxipvggaqlkl2l9jpd5czbc4c2pcnpg3";
 
+  aarch64Patch = fetchpatch {
+    url = https://reviews.llvm.org/file/data/2oqw5rhhklsapbjrhlpd/PHID-FILE-lvo4fcs6hjvkxb5wneg2/D40423.diff;
+    sha256 = "0b0h7n7lxw33pn2j061hm9050zn263gmiig937g5cmcvjimxlybb";
+  };
+
   # Used when creating a version-suffixed symlink of libLLVM.dylib
   shortVersion = with stdenv.lib;
     concatStringsSep "." (take 2 (splitString "." release_version));
@@ -75,6 +80,8 @@ in stdenv.mkDerivation rec {
 
     # Revert compiler-rt commit that makes codesign mandatory
     patch -p1 -i ${./compiler-rt-codesign.patch} -d projects/compiler-rt
+  '' + stdenv.lib.optionalString stdenv.isAarch64 ''
+    patch -p0 < ${aarch64Patch}
   '';
 
   # hacky fix: created binaries need to be run before installation