diff --git a/old-configure.in b/old-configure.in
index 6f749513bdd1..dac5a8151a0f 100644
--- a/old-configure.in
+++ b/old-configure.in
@@ -2212,12 +2212,17 @@ if test -n "$MOZ_ANGLE_RENDERER"; then
 
   # Find a D3D compiler DLL in a Windows SDK.
   MOZ_D3DCOMPILER_VISTA_DLL=
-  case "$MOZ_WINSDK_MAXVER" in
-  0x0603*|0x0A00*)
+  if test "$OS_ARCH" != "$HOST_OS_ARCH"; then
     MOZ_D3DCOMPILER_VISTA_DLL=d3dcompiler_47.dll
-    AC_MSG_RESULT([Found D3D compiler in Windows SDK.])
-  ;;
-  esac
+    AC_MSG_RESULT([Assuming D3D compiler will be in fxc2.])
+  else
+    case "$MOZ_WINSDK_MAXVER" in
+    0x0603*|0x0A00*)
+      MOZ_D3DCOMPILER_VISTA_DLL=d3dcompiler_47.dll
+      AC_MSG_RESULT([Found D3D compiler in Windows SDK.])
+    ;;
+    esac
+  fi
 
   if test -n "$MOZ_D3DCOMPILER_VISTA_DLL"; then
     # We have a name, now track down the path.
@@ -2235,13 +2240,20 @@ if test -n "$MOZ_ANGLE_RENDERER"; then
         MOZ_D3DCOMPILER_VISTA_DLL_PATH=
       fi
     else
-      AC_MSG_RESULT([Windows SDK not found.])
+      MOZ_D3DCOMPILER_VISTA_DLL_PATH="$(dirname $FXC)/$MOZ_D3DCOMPILER_VISTA_DLL"
+      if test -f "$MOZ_D3DCOMPILER_VISTA_DLL_PATH"; then
+        AC_MSG_RESULT([Found MOZ_D3DCOMPILER_VISTA_DLL_PATH: $MOZ_D3DCOMPILER_VISTA_DLL_PATH])
+      else
+        AC_MSG_RESULT([MOZ_D3DCOMPILER_VISTA_DLL_PATH doesn't exist: $MOZ_D3DCOMPILER_VISTA_DLL_PATH])
+        AC_MSG_ERROR([fxc2 or "$MOZ_D3DCOMPILER_VISTA_DLL" seem to be missing from the expected location.])
+        MOZ_D3DCOMPILER_VISTA_DLL_PATH=
+      fi
     fi
   else
     if test "$OS_ARCH" = "$HOST_OS_ARCH"; then
       AC_MSG_ERROR([Couldn't find Windows SDK 8.1 or higher needed for ANGLE.])
     else
-      AC_MSG_RESULT([Windows SDK not needed for ANGLE in Linux MinGW build.])
+      AC_MSG_ERROR([We should need "$MOZ_D3DCOMPILER_VISTA_DLL" for ANGLE in Linux MinGW build, but we didn't look for it.])
     fi
   fi
 
@@ -2263,10 +2275,8 @@ if test -n "$MOZ_ANGLE_RENDERER"; then
     AC_MSG_RESULT([Found d3dcompiler DLL for Vista+: $MOZ_D3DCOMPILER_VISTA_DLL])
   fi
 
-  if test -z "$CROSS_COMPILE"; then
-    if test -z "MOZ_FOUND_A_D3D_COMPILER"; then
-      AC_MSG_ERROR([Couldn't find an acceptable D3D compiler DLL.])
-    fi
+  if test -z "MOZ_FOUND_A_D3D_COMPILER"; then
+    AC_MSG_ERROR([Couldn't find an acceptable D3D compiler DLL.])
   fi
 fi # MOZ_ANGLE_RENDERER
 
diff --git a/toolkit/moz.configure b/toolkit/moz.configure
index 6219cb710a28..616f728a8bd9 100644
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -1293,6 +1293,7 @@ set_config('MOZ_LAYOUT_DEBUGGER', depends_if('--enable-layout-debugger')(lambda
 with only_when(compile_environment):
     fxc = check_prog('FXC', ('fxc.exe', 'fxc2.exe'), when=depends(target)
                      (lambda t: t.kernel == 'WINNT'))
+    add_old_configure_assignment('FXC', fxc)
     wine = check_prog('WINE', ['wine'], when=depends(target, host)
                       (lambda t, h: t.kernel == 'WINNT' and h.kernel == 'Linux'))