diff --git a/pkgs/development/interpreters/luajit/default.nix b/pkgs/development/interpreters/luajit/default.nix
index c95b9e8b8e37..abd1fda47cb6 100644
--- a/pkgs/development/interpreters/luajit/default.nix
+++ b/pkgs/development/interpreters/luajit/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, lib, fetchurl
+{ stdenv, lib, fetchurl, buildPackages
 , name ? "luajit-${version}"
 , isStable
 , sha256
@@ -20,24 +20,23 @@ stdenv.mkDerivation rec {
 
   luaversion = "5.1";
 
-  patchPhase = ''
-    substituteInPlace Makefile \
-      --replace /usr/local "$out"
-
-    substituteInPlace src/Makefile --replace gcc cc
-  '' + stdenv.lib.optionalString (stdenv.cc.libc != null)
-  ''
-    substituteInPlace Makefile \
-      --replace ldconfig ${stdenv.cc.libc.bin or stdenv.cc.libc}/bin/ldconfig
+  postPatch = ''
+    substituteInPlace Makefile --replace ldconfig :
   '';
 
   configurePhase = false;
 
+  makeFlags = [
+    "PREFIX=$(out)"
+    "DEFAULT_CC=cc"
+    "CROSS=${stdenv.cc.targetPrefix}"
+    # TODO: when pointer size differs, we would need e.g. -m32
+    "HOST_CC=${buildPackages.stdenv.cc}/bin/cc"
+  ];
   buildFlags = [ "amalg" ]; # Build highly optimized version
   enableParallelBuilding = true;
 
-  installPhase   = ''
-      make install PREFIX="$out"
+  postInstall = ''
       ( cd "$out/include"; ln -s luajit-*/* . )
       ln -s "$out"/bin/luajit-* "$out"/bin/lua
     ''
diff --git a/pkgs/development/libraries/lmdb/default.nix b/pkgs/development/libraries/lmdb/default.nix
index 047a74f08409..9d57d4721820 100644
--- a/pkgs/development/libraries/lmdb/default.nix
+++ b/pkgs/development/libraries/lmdb/default.nix
@@ -18,7 +18,11 @@ stdenv.mkDerivation rec {
 
   outputs = [ "bin" "out" "dev" ];
 
-  makeFlags = [ "prefix=$(out)" "CC=cc" ]
+  makeFlags = [
+    "prefix=$(out)"
+    "CC=${stdenv.cc.targetPrefix}cc"
+    "AR=${stdenv.cc.targetPrefix}ar"
+  ]
     ++ stdenv.lib.optional stdenv.isDarwin "LDFLAGS=-Wl,-install_name,$(out)/lib/liblmdb.so";
 
   doCheck = true;
diff --git a/pkgs/servers/dns/knot-resolver/default.nix b/pkgs/servers/dns/knot-resolver/default.nix
index 2affc8ceff25..04d0a0cf8d0c 100644
--- a/pkgs/servers/dns/knot-resolver/default.nix
+++ b/pkgs/servers/dns/knot-resolver/default.nix
@@ -19,6 +19,11 @@ unwrapped = stdenv.mkDerivation rec {
     sha256 = "d1396888ec3a63f19dccdf2b7dbcb0d16a5d8642766824b47f4c21be90ce362b";
   };
 
+  # Short-lived cross fix, as upstream is migrating to meson anyway.
+  postPatch = ''
+    substituteInPlace platform.mk --replace "objdump" "$OBJDUMP"
+  '';
+
   outputs = [ "out" "dev" ];
 
   configurePhase = "patchShebangs scripts/";