diff --git a/dlls/mshtml/protocol.c b/dlls/mshtml/protocol.c
index 6f5b6be866..c0a1aa389e 100644
--- a/dlls/mshtml/protocol.c
+++ b/dlls/mshtml/protocol.c
@@ -32,6 +32,15 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(mshtml);
 
+/* On https://docs.microsoft.com/en-us/previous-versions//aa767740(v=vs.85)
+ * the only mentioned resource types are RT_HTML and RT_FILE.
+ * RT_FILE is completely undocumented and doesn't appear in any headers,
+ * but by a process of elimination, the 2110 magic number used in
+ * https://www.codeproject.com/Articles/435/How-to-use-the-res-protocol-in-Developer-Studio
+ * must be RT_FILE.
+ */
+#define RT_FILE MAKEINTRESOURCE(2110)
+
 typedef struct {
     IUnknown          IUnknown_inner;
     IInternetProtocol IInternetProtocol_iface;
@@ -540,6 +549,7 @@ static HRESULT WINAPI ResProtocol_Start(IInternetProtocol *iface, LPCWSTR szUrl,
 {
     InternetProtocol *This = impl_from_IInternetProtocol(iface);
     WCHAR *url_dll, *url_file, *url, *mime, *res_type = (LPWSTR)RT_HTML, *ptr;
+    BOOL restype_defaulted = FALSE;
     DWORD grfBINDF = 0, len;
     BINDINFO bindinfo;
     HMODULE hdll;
@@ -594,6 +604,7 @@ static HRESULT WINAPI ResProtocol_Start(IInternetProtocol *iface, LPCWSTR szUrl,
     }else {
         url_file = res_type;
         res_type = (LPWSTR)RT_HTML;
+        restype_defaulted = TRUE;
     }
 
     /* Ignore query and hash parts. */
@@ -613,12 +624,16 @@ static HRESULT WINAPI ResProtocol_Start(IInternetProtocol *iface, LPCWSTR szUrl,
     TRACE("trying to find resource type %s, name %s\n", debugstr_w(res_type), debugstr_w(url_file));
 
     src = FindResourceW(hdll, url_file, res_type);
+    if(!src && restype_defaulted)
+        src = FindResourceW(hdll, url_file, (LPCWSTR)RT_FILE);
     if(!src) {
         LPWSTR endpoint = NULL;
         DWORD file_id = wcstol(url_file, &endpoint, 10);
-        if(endpoint == url_file+lstrlenW(url_file))
+        if(!*endpoint) {
             src = FindResourceW(hdll, MAKEINTRESOURCEW(file_id), res_type);
-
+            if(!src && restype_defaulted)
+                src = FindResourceW(hdll, MAKEINTRESOURCEW(file_id), (LPCWSTR)RT_FILE);
+        }
         if(!src) {
             WARN("Could not find resource\n");
             IInternetProtocolSink_ReportResult(pOIProtSink,
diff --git a/dlls/mshtml/tests/protocol.c b/dlls/mshtml/tests/protocol.c
index 75063f5ecf..66382507f2 100644
--- a/dlls/mshtml/tests/protocol.c
+++ b/dlls/mshtml/tests/protocol.c
@@ -262,6 +262,44 @@ static void protocol_start(IInternetProtocol *protocol, const WCHAR *url)
     CHECK_CALLED(ReportResult);
 }
 
+static void test_res_url_fail(const char *url_suffix, HRESULT expected_hres,
+        BOOL expect_win32err)
+{
+    WCHAR url[INTERNET_MAX_URL_LENGTH];
+    IInternetProtocol *protocol;
+    HRESULT hres;
+
+    memcpy(url, res_url_base, res_url_base_len*sizeof(WCHAR));
+    MultiByteToWideChar(CP_ACP, 0, url_suffix, -1, url+res_url_base_len, ARRAY_SIZE(url)-res_url_base_len);
+
+    hres = CoCreateInstance(&CLSID_ResProtocol, NULL, CLSCTX_INPROC_SERVER, &IID_IInternetProtocol, (void**)&protocol);
+    ok(hres == S_OK, "Could not create ResProtocol instance: %08x\n", hres);
+
+    SET_EXPECT(GetBindInfo);
+    SET_EXPECT(ReportResult);
+    if (SUCCEEDED(expected_hres)) {
+        SET_EXPECT(ReportProgress);
+        SET_EXPECT(ReportData);
+    }
+    expect_hrResult = expected_hres;
+    expect_hr_win32err = expect_win32err;
+    hres = IInternetProtocol_Start(protocol, url, &protocol_sink, &bind_info, 0, 0);
+    if (expect_win32err)
+        ok((hres&0xffff0000) == ((FACILITY_WIN32 << 16)|0x80000000) || hres == expected_hres,
+                "%s: expected win32 err or %08x got: %08x\n", url_suffix, expected_hres, hres);
+    else
+        ok(hres == expected_hres, "%s: expected: %08x got: %08x\n", url_suffix, expected_hres, hres);
+
+
+    CHECK_CALLED(GetBindInfo);
+    if (SUCCEEDED(expected_hres)) {
+        CHECK_CALLED(ReportProgress);
+        CHECK_CALLED(ReportData);
+    }
+    CHECK_CALLED(ReportResult);
+    IInternetProtocol_Release(protocol);
+}
+
 static void test_res_url(const char *url_suffix)
 {
     WCHAR url[INTERNET_MAX_URL_LENGTH];
@@ -604,6 +642,17 @@ static void test_res_protocol(void)
     test_res_url("/23/123");
 
     test_res_url("/jstest.html");
+    test_res_url("/jstest-rtfile.html");
+    test_res_url("/#2110/jstest-rtfile.html");
+    test_res_url("/2110/jstest-rtfile.html");
+    /* won't fall back to RT_FILE from: */
+    /* - invalid string resource type: */
+    test_res_url_fail("/doesntexist/jstest-rtfile.html", HRESULT_FROM_WIN32(ERROR_RESOURCE_TYPE_NOT_FOUND), TRUE);
+    /* - other numeric resource types (eg. 2 = RT_BITMAP): */
+    test_res_url_fail("/2/jstest-rtfile.html", HRESULT_FROM_WIN32(ERROR_RESOURCE_TYPE_NOT_FOUND), TRUE);
+    /* - even from 23 = RT_HTML: */
+    test_res_url_fail("/23/jstest-rtfile.html", HRESULT_FROM_WIN32(ERROR_RESOURCE_TYPE_NOT_FOUND), TRUE);
+
     test_res_url("/Test/res.html");
     test_res_url("/test/dir/dir2/res.html");
 
diff --git a/dlls/mshtml/tests/rsrc.rc b/dlls/mshtml/tests/rsrc.rc
index 05bc836ac6..12e95b7456 100644
--- a/dlls/mshtml/tests/rsrc.rc
+++ b/dlls/mshtml/tests/rsrc.rc
@@ -28,6 +28,9 @@ asyncscriptload.js HTML "asyncscriptload.js"
 /* @makedep: jstest.html */
 jstest.html HTML "jstest.html"
 
+/* @makedep: jstest.html */
+jstest-rtfile.html 2110 "jstest.html"
+
 /* @makedep: vbtest.html */
 vbtest.html HTML "vbtest.html"