diff --git a/dlls/advpack/advpack_private.h b/dlls/advpack/advpack_private.h
index cbbbf4819af..a1bcfe44eb0 100644
--- a/dlls/advpack/advpack_private.h
+++ b/dlls/advpack/advpack_private.h
@@ -27,4 +27,27 @@ void set_ldids(HINF hInf, LPCWSTR pszInstallSection, LPCWSTR pszWorkingDir) DECL
 
 HRESULT launch_exe(LPCWSTR cmd, LPCWSTR dir, HANDLE *phEXE) DECLSPEC_HIDDEN;
 
+static inline void *heap_alloc(size_t len)
+{
+    return HeapAlloc(GetProcessHeap(), 0, len);
+}
+
+static inline BOOL heap_free(void *mem)
+{
+    return HeapFree(GetProcessHeap(), 0, mem);
+}
+
+static inline char *heap_strdupWtoA(const WCHAR *str)
+{
+    char *ret = NULL;
+
+    if(str) {
+        size_t size = WideCharToMultiByte(CP_ACP, 0, str, -1, NULL, 0, NULL, NULL);
+        ret = heap_alloc(size);
+        WideCharToMultiByte(CP_ACP, 0, str, -1, ret, size, NULL, NULL);
+    }
+
+    return ret;
+}
+
 #endif /* __ADVPACK_PRIVATE_H */
diff --git a/dlls/advpack/files.c b/dlls/advpack/files.c
index f6056f298fc..c34f6d566cc 100644
--- a/dlls/advpack/files.c
+++ b/dlls/advpack/files.c
@@ -779,11 +779,39 @@ done:
 HRESULT WINAPI ExtractFilesW(LPCWSTR CabName, LPCWSTR ExpandDir, DWORD Flags,
                              LPCWSTR FileList, LPVOID LReserved, DWORD Reserved)
 {
+    char *cab_name = NULL, *expand_dir = NULL, *file_list = NULL;
+    HRESULT hres = S_OK;
 
-    FIXME("(%s, %s, %d, %s, %p, %d) stub!\n", debugstr_w(CabName), debugstr_w(ExpandDir),
+    TRACE("(%s, %s, %d, %s, %p, %d)\n", debugstr_w(CabName), debugstr_w(ExpandDir),
           Flags, debugstr_w(FileList), LReserved, Reserved);
 
-    return E_FAIL;
+    if(CabName) {
+        cab_name = heap_strdupWtoA(CabName);
+        if(!cab_name)
+            return E_OUTOFMEMORY;
+    }
+
+    if(ExpandDir) {
+        expand_dir = heap_strdupWtoA(ExpandDir);
+        if(!expand_dir)
+            hres = E_OUTOFMEMORY;
+    }
+
+    if(SUCCEEDED(hres) && FileList) {
+        file_list = heap_strdupWtoA(FileList);
+        if(!file_list)
+            hres = E_OUTOFMEMORY;
+    }
+
+    /* cabinet.dll, which does the real job of extracting files, doesn't have UNICODE API,
+       so we need W->A conversion at some point anyway. */
+    if(SUCCEEDED(hres))
+        hres = ExtractFilesA(cab_name, expand_dir, Flags, file_list, LReserved, Reserved);
+
+    heap_free(cab_name);
+    heap_free(expand_dir);
+    heap_free(file_list);
+    return hres;
 }
 
 /***********************************************************************
diff --git a/dlls/advpack/tests/files.c b/dlls/advpack/tests/files.c
index 9bb8cdeb1e0..4a985bed22e 100644
--- a/dlls/advpack/tests/files.c
+++ b/dlls/advpack/tests/files.c
@@ -32,6 +32,7 @@
 static HMODULE hAdvPack;
 static HRESULT (WINAPI *pAddDelBackupEntry)(LPCSTR, LPCSTR, LPCSTR, DWORD);
 static HRESULT (WINAPI *pExtractFiles)(LPCSTR, LPCSTR, DWORD, LPCSTR, LPVOID, DWORD);
+static HRESULT (WINAPI *pExtractFilesW)(const WCHAR*,const WCHAR*,DWORD,const WCHAR*,void*,DWORD);
 static HRESULT (WINAPI *pAdvInstallFile)(HWND,LPCSTR,LPCSTR,LPCSTR,LPCSTR,DWORD,DWORD);
 
 static CHAR CURR_DIR[MAX_PATH];
@@ -44,6 +45,7 @@ static void init_function_pointers(void)
     {
         pAddDelBackupEntry = (void *)GetProcAddress(hAdvPack, "AddDelBackupEntry");
         pExtractFiles = (void *)GetProcAddress(hAdvPack, "ExtractFiles");
+        pExtractFilesW = (void *)GetProcAddress(hAdvPack, "ExtractFilesW");
         pAdvInstallFile = (void*)GetProcAddress(hAdvPack, "AdvInstallFile");
     }
 }
@@ -468,6 +470,23 @@ static void test_ExtractFiles(void)
     ok(!DeleteFileA("dest\\a.txt"), "Expected dest\\a.txt to not exist\n");
     ok(!DeleteFileA("dest\\testdir\\c.txt"), "Expected dest\\testdir\\c.txt to not exist\n");
     ok(!RemoveDirectoryA("dest\\testdir"), "Expected dest\\testdir to not exist\n");
+
+    if(pExtractFilesW) {
+        static const WCHAR extract_cabW[] = {'e','x','t','r','a','c','t','.','c','a','b',0};
+        static const WCHAR destW[] = {'d','e','s','t',0};
+        static const WCHAR file_listW[] =
+            {'a','.','t','x','t',':','t','e','s','t','d','i','r','\\','c','.','t','x','t',0};
+
+        hr = pExtractFilesW(extract_cabW, destW, 0, file_listW, NULL, 0);
+        ok(hr == S_OK, "Expected S_OK, got %08x\n", hr);
+        ok(DeleteFileA("dest\\a.txt"), "Expected dest\\a.txt to exist\n");
+        ok(DeleteFileA("dest\\testdir\\c.txt"), "Expected dest\\testdir\\c.txt to exist\n");
+        ok(RemoveDirectoryA("dest\\testdir"), "Expected dest\\testdir to exist\n");
+        ok(!DeleteFileA("dest\\b.txt"), "Expected dest\\b.txt to not exist\n");
+        ok(!DeleteFileA("dest\\testdir\\d.txt"), "Expected dest\\testdir\\d.txt to not exist\n");
+    }else {
+        win_skip("ExtractFilesW not available\n");
+    }
 }
 
 static void test_AdvInstallFile(void)