diff --git a/dlls/urlmon/tests/misc.c b/dlls/urlmon/tests/misc.c
index 425de1be1c3..d759961e860 100644
--- a/dlls/urlmon/tests/misc.c
+++ b/dlls/urlmon/tests/misc.c
@@ -339,6 +339,8 @@ static const WCHAR mimeImageXPng[] = {'i','m','a','g','e','/','x','-','p','n','g
 static const WCHAR mimeImageTiff[] = {'i','m','a','g','e','/','t','i','f','f',0};
 static const WCHAR mimeVideoAvi[] = {'v','i','d','e','o','/','a','v','i',0};
 static const WCHAR mimeVideoMpeg[] = {'v','i','d','e','o','/','m','p','e','g',0};
+static const WCHAR mimeAppXGzip[] = {'a','p','p','l','i','c','a','t','i','o','n','/',
+                                    'x','-','g','z','i','p','-','c','o','m','p','r','e','s','s','e','d',0};
 
 static const struct {
     LPCWSTR url;
@@ -407,6 +409,10 @@ static BYTE data51[] = {0x00,0x00,0x01,0xba,0xff};
 static BYTE data52[] = {0x00,0x00,0x01,0xb8,0xff};
 static BYTE data53[] = {0x00,0x00,0x01,0xba};
 static BYTE data54[] = {0x00,0x00,0x01,0xba,'<','h','t','m','l','>'};
+static BYTE data55[] = {0x1f,0x8b,'x'};
+static BYTE data56[] = {0x1f};
+static BYTE data57[] = {0x1f,0x8b,'<','h','t','m','l','>','t','e','s','t',0};
+static BYTE data58[] = {0x1f,0x8b};
 
 static const struct {
     BYTE *data;
@@ -466,7 +472,11 @@ static const struct {
     {data51, sizeof(data51), mimeVideoMpeg},
     {data52, sizeof(data52), mimeAppOctetStream},
     {data53, sizeof(data53), mimeAppOctetStream},
-    {data54, sizeof(data54), mimeTextHtml}
+    {data54, sizeof(data54), mimeTextHtml},
+    {data55, sizeof(data55), mimeAppXGzip},
+    {data56, sizeof(data56), mimeTextPlain},
+    {data57, sizeof(data57), mimeTextHtml},
+    {data58, sizeof(data58), mimeAppOctetStream}
 };
 
 static void test_FindMimeFromData(void)
diff --git a/dlls/urlmon/urlmon_main.c b/dlls/urlmon/urlmon_main.c
index d36803c4ab8..fca51505684 100644
--- a/dlls/urlmon/urlmon_main.c
+++ b/dlls/urlmon/urlmon_main.c
@@ -469,6 +469,11 @@ static BOOL video_mpeg_filter(const BYTE const *b, DWORD size)
         && (b[3] == 0xb3 || b[3] == 0xba);
 }
 
+static BOOL application_xgzip_filter(const BYTE const *b, DWORD size)
+{
+    return size > 2 && b[0] == 0x1f && b[1] == 0x8b;
+}
+
 static BOOL text_plain_filter(const BYTE const *b, DWORD size)
 {
     const BYTE *ptr;
@@ -529,6 +534,8 @@ HRESULT WINAPI FindMimeFromData(LPBC pBC, LPCWSTR pwzUrl, LPVOID pBuffer,
         static const WCHAR wszImageBmp[] = {'i','m','a','g','e','/','b','m','p',0};
         static const WCHAR wszVideoAvi[] = {'v','i','d','e','o','/','a','v','i',0};
         static const WCHAR wszVideoMpeg[] = {'v','i','d','e','o','/','m','p','e','g',0};
+        static const WCHAR wszAppXGzip[] = {'a','p','p','l','i','c','a','t','i','o','n','/',
+            'x','-','g','z','i','p','-','c','o','m','p','r','e','s','s','e','d',0};
         static const WCHAR wszTextPlain[] = {'t','e','x','t','/','p','l','a','i','n','\0'};
         static const WCHAR wszAppOctetStream[] = {'a','p','p','l','i','c','a','t','i','o','n','/',
             'o','c','t','e','t','-','s','t','r','e','a','m','\0'};
@@ -545,6 +552,7 @@ HRESULT WINAPI FindMimeFromData(LPBC pBC, LPCWSTR pwzUrl, LPVOID pBuffer,
             {wszImageBmp,       image_bmp_filter},
             {wszVideoAvi,       video_avi_filter},
             {wszVideoMpeg,      video_mpeg_filter},
+            {wszAppXGzip,       application_xgzip_filter},
             {wszTextPlain,      text_plain_filter},
             {wszAppOctetStream, application_octet_stream_filter}
         };