diff --git a/pkgs/development/compilers/llvm/6/llvm.nix b/pkgs/development/compilers/llvm/6/llvm.nix
index 328f95f11b3..54617a07573 100644
--- a/pkgs/development/compilers/llvm/6/llvm.nix
+++ b/pkgs/development/compilers/llvm/6/llvm.nix
@@ -13,7 +13,8 @@
 , fetchpatch
 , debugVersion ? false
 , enableManpages ? false
-, enableTargets ? [ stdenv.hostPlatform stdenv.targetPlatform ]
+# Mesa requires AMDGPU target
+, enableTargets ? [ stdenv.hostPlatform stdenv.targetPlatform "AMDGPU" ]
 , enableSharedLibraries ? true
 }:
 
diff --git a/pkgs/development/compilers/llvm/7/llvm.nix b/pkgs/development/compilers/llvm/7/llvm.nix
index 2ef6b147214..a852822cddc 100644
--- a/pkgs/development/compilers/llvm/7/llvm.nix
+++ b/pkgs/development/compilers/llvm/7/llvm.nix
@@ -14,7 +14,8 @@
 , debugVersion ? false
 , enableManpages ? false
 , enableSharedLibraries ? true
-, enableTargets ? [ stdenv.hostPlatform stdenv.targetPlatform ]
+# Mesa requires AMDGPU target
+, enableTargets ? [ stdenv.hostPlatform stdenv.targetPlatform "AMDGPU" ]
 , enablePFM ? !stdenv.isDarwin
 }:
 
diff --git a/pkgs/development/compilers/llvm/common.nix b/pkgs/development/compilers/llvm/common.nix
index e4f55963a6f..27f48ff3f11 100644
--- a/pkgs/development/compilers/llvm/common.nix
+++ b/pkgs/development/compilers/llvm/common.nix
@@ -2,7 +2,9 @@
 
 rec {
   llvmBackend = platform:
-    if platform.parsed.cpu.family == "x86" then
+    if builtins.typeOf platform == "string" then
+      platform
+    else if platform.parsed.cpu.family == "x86" then
       "X86"
     else if platform.parsed.cpu.name == "aarch64" then
       "AArch64"