diff --git a/build/moz.configure/toolchain.configure b/build/moz.configure/toolchain.configure
index 2abd4201807c..76c5f1ad6cbd 100755
--- a/build/moz.configure/toolchain.configure
+++ b/build/moz.configure/toolchain.configure
@@ -548,6 +548,16 @@ def is_windows(target, host):
     return host.kernel == "WINNT" or target.kernel == "WINNT"
 
 
+# Calling this a sysroot is a little weird, but it's the terminology clang went
+# with with its -winsysroot flag.
+option(
+    env="WINSYSROOT",
+    nargs=1,
+    when=is_windows,
+    help='Path to a Windows "sysroot" (directory containing MSVC, SDKs)',
+)
+
+
 option(
     env="VC_PATH",
     nargs=1,
@@ -561,12 +571,21 @@ option(
     vs_version,
     build_environment,
     "VC_PATH",
+    "WINSYSROOT",
     when=is_windows,
 )
+@imports("os")
 @imports(_from="operator", _import="itemgetter")
-def vc_compiler_paths_for_version(host, vs_version, env, vc_path):
-    if vc_path and vs_version:
-        die("VC_PATH and --with-visual-studio-version cannot be used together.")
+def vc_compiler_paths_for_version(host, vs_version, env, vc_path, winsysroot):
+    if (vc_path or winsysroot) and vs_version:
+        var = "VC_PATH" if vc_path else "WINSYSROOT"
+        die(f"{var} and --with-visual-studio-version cannot be used together.")
+    if winsysroot:
+        if vc_path:
+            die("WINSYSROOT and VC_PATH cannot be set together.")
+        base_vc_path = os.path.join(winsysroot[0], "VC", "Tools", "MSVC")
+        versions = os.listdir(base_vc_path)
+        vc_path = [os.path.join(base_vc_path, str(max(Version(v) for v in versions)))]
     if vc_path:
         # Use an arbitrary version, it doesn't matter.
         all_versions = [(Version("15"), vc_path[0])]
diff --git a/build/moz.configure/windows.configure b/build/moz.configure/windows.configure
index b4236001cf7c..637d9ff0b098 100644
--- a/build/moz.configure/windows.configure
+++ b/build/moz.configure/windows.configure
@@ -31,15 +31,20 @@ def valid_windows_version(value):
 option(env="WINDOWSSDKDIR", nargs=1, help="Directory containing the Windows SDK")
 
 
-@depends("WINDOWSSDKDIR", c_compiler, host_c_compiler)
-def windows_sdk_dir(value, compiler, host_compiler):
+@depends("WINDOWSSDKDIR", "WINSYSROOT", c_compiler, host_c_compiler)
+def windows_sdk_dir(value, winsysroot, compiler, host_compiler):
     if value:
+        if winsysroot:
+            die("WINDOWSSDKDIR and WINSYSROOT cannot be set together.")
         return value
     # Ideally, we'd actually check for host/target ABI being MSVC, but
     # that's waiting for bug 1617793.
     if compiler.type != "clang-cl" and host_compiler.type != "clang-cl":
         return ()
 
+    if winsysroot:
+        return [os.path.join(winsysroot[0], "Windows Kits", "10")]
+
     return set(
         normalize_path(x[1])
         for x in get_registry_values(
diff --git a/build/mozconfig.no-compile b/build/mozconfig.no-compile
index 4632fabe0108..68dc06fb12ec 100644
--- a/build/mozconfig.no-compile
+++ b/build/mozconfig.no-compile
@@ -18,8 +18,7 @@ unset BINDGEN_CFLAGS
 unset ENABLE_CLANG_PLUGIN
 unset MACOS_SDK_DIR
 unset MACOS_PRIVATE_FRAMEWORKS_DIR
-unset VC_PATH
-unset WINDOWSSDKDIR
+unset WINSYSROOT
 unset MOZ_LTO
 
 unset MOZ_STDCXX_COMPAT
diff --git a/build/win32/mozconfig.vs2017 b/build/win32/mozconfig.vs2017
index ba607f3bfe65..967da8682d72 100644
--- a/build/win32/mozconfig.vs2017
+++ b/build/win32/mozconfig.vs2017
@@ -3,10 +3,9 @@ if [ -z "${VSPATH}" ]; then
 fi
 
 if [ -d "${VSPATH}" ]; then
-    export WINDOWSSDKDIR="${VSPATH}/windows kits/10"
     export WIN32_REDIST_DIR="${VSPATH}/vc/redist/msvc/14.16.27012/x86/microsoft.vc141.crt"
     export WIN_UCRT_REDIST_DIR="${VSPATH}/windows kits/10/redist/ucrt/dlls/x86"
-    export VC_PATH="${VSPATH}/vc/tools/msvc/14.16.27023"
+    export WINSYSROOT="${VSPATH}"
 fi
 
 ac_add_options --target=i686-pc-mingw32
diff --git a/build/win64-aarch64/mozconfig.vs2017 b/build/win64-aarch64/mozconfig.vs2017
index b687ea8dff74..db732613121f 100644
--- a/build/win64-aarch64/mozconfig.vs2017
+++ b/build/win64-aarch64/mozconfig.vs2017
@@ -3,7 +3,6 @@ if [ -z "${VSPATH}" ]; then
 fi
 
 if [ -d "${VSPATH}" ]; then
-    export WINDOWSSDKDIR="${VSPATH}/windows kits/10"
     export WIN32_REDIST_DIR="${VSPATH}/vc/redist/msvc/14.16.27012/arm64/microsoft.vc141.crt"
-    export VC_PATH="${VSPATH}/vc/tools/msvc/14.16.27023"
+    export WINSYSROOT="${VSPATH}"
 fi
diff --git a/build/win64/mozconfig.vs2017 b/build/win64/mozconfig.vs2017
index ec9a1f25baed..5e33a537d8c1 100644
--- a/build/win64/mozconfig.vs2017
+++ b/build/win64/mozconfig.vs2017
@@ -3,8 +3,7 @@ if [ -z "${VSPATH}" ]; then
 fi
 
 if [ -d "${VSPATH}" ]; then
-    export WINDOWSSDKDIR="${VSPATH}/windows kits/10"
     export WIN32_REDIST_DIR=${VSPATH}/vc/redist/msvc/14.16.27012/x64/microsoft.vc141.crt
     export WIN_UCRT_REDIST_DIR="${VSPATH}/windows kits/10/redist/ucrt/dlls/x64"
-    export VC_PATH="${VSPATH}/vc/tools/msvc/14.16.27023"
+    export WINSYSROOT="${VSPATH}"
 fi