diff --git a/dlls/api-ms-win-core-path-l1-1-0/api-ms-win-core-path-l1-1-0.spec b/dlls/api-ms-win-core-path-l1-1-0/api-ms-win-core-path-l1-1-0.spec
index a09889f4151..61eb22031e9 100644
--- a/dlls/api-ms-win-core-path-l1-1-0/api-ms-win-core-path-l1-1-0.spec
+++ b/dlls/api-ms-win-core-path-l1-1-0/api-ms-win-core-path-l1-1-0.spec
@@ -10,7 +10,7 @@
 @ stub PathCchCombine
 @ stub PathCchCombineEx
 @ stdcall PathCchFindExtension(wstr long ptr) kernelbase.PathCchFindExtension
-@ stub PathCchIsRoot
+@ stdcall PathCchIsRoot(wstr) kernelbase.PathCchIsRoot
 @ stub PathCchRemoveBackslash
 @ stub PathCchRemoveBackslashEx
 @ stdcall PathCchRemoveExtension(wstr long) kernelbase.PathCchRemoveExtension
diff --git a/dlls/kernelbase/kernelbase.spec b/dlls/kernelbase/kernelbase.spec
index aefc63e54c9..ffb5a957210 100644
--- a/dlls/kernelbase/kernelbase.spec
+++ b/dlls/kernelbase/kernelbase.spec
@@ -1039,7 +1039,7 @@
 # @ stub PathCchCombine
 # @ stub PathCchCombineEx
 @ stdcall PathCchFindExtension(wstr long ptr)
-# @ stub PathCchIsRoot
+@ stdcall PathCchIsRoot(wstr)
 # @ stub PathCchRemoveBackslash
 # @ stub PathCchRemoveBackslashEx
 @ stdcall PathCchRemoveExtension(wstr long)
diff --git a/dlls/kernelbase/path.c b/dlls/kernelbase/path.c
index 88990d14a43..75faf0b79c3 100644
--- a/dlls/kernelbase/path.c
+++ b/dlls/kernelbase/path.c
@@ -240,6 +240,44 @@ HRESULT WINAPI PathCchFindExtension(const WCHAR *path, SIZE_T size, const WCHAR
     return S_OK;
 }
 
+BOOL WINAPI PathCchIsRoot(const WCHAR *path)
+{
+    const WCHAR *root_end;
+    const WCHAR *next;
+    BOOL is_unc;
+
+    TRACE("%s\n", wine_dbgstr_w(path));
+
+    if (!path || !*path) return FALSE;
+
+    root_end = get_root_end(path);
+    if (!root_end) return FALSE;
+
+    if ((is_unc = is_prefixed_unc(path)) || (path[0] == '\\' && path[1] == '\\' && path[2] != '?'))
+    {
+        next = root_end + 1;
+        /* No extra segments */
+        if ((is_unc && !*next) || (!is_unc && !*next)) return TRUE;
+
+        /* Has first segment with an ending backslash but no remaining characters */
+        if (get_next_segment(next, &next) && !*next) return FALSE;
+        /* Has first segment with no ending backslash */
+        else if (!*next)
+            return TRUE;
+        /* Has first segment with an ending backslash and has remaining characters*/
+        else
+        {
+            next++;
+            /* Second segment must have no backslash and no remaining characters */
+            return !get_next_segment(next, &next) && !*next;
+        }
+    }
+    else if (*root_end == '\\' && !root_end[1])
+        return TRUE;
+    else
+        return FALSE;
+}
+
 HRESULT WINAPI PathCchRemoveExtension(WCHAR *path, SIZE_T size)
 {
     const WCHAR *extension;
diff --git a/dlls/kernelbase/tests/path.c b/dlls/kernelbase/tests/path.c
index 1cbeb8b4051..2edd49b0af2 100644
--- a/dlls/kernelbase/tests/path.c
+++ b/dlls/kernelbase/tests/path.c
@@ -35,6 +35,7 @@ HRESULT (WINAPI *pPathCchAddBackslashEx)(WCHAR *out, SIZE_T size, WCHAR **endptr
 HRESULT (WINAPI *pPathCchAddExtension)(WCHAR *path, SIZE_T size, const WCHAR *extension);
 HRESULT (WINAPI *pPathCchCombineEx)(WCHAR *out, SIZE_T size, const WCHAR *path1, const WCHAR *path2, DWORD flags);
 HRESULT (WINAPI *pPathCchFindExtension)(const WCHAR *path, SIZE_T size, const WCHAR **extension);
+BOOL    (WINAPI *pPathCchIsRoot)(const WCHAR *path);
 HRESULT (WINAPI *pPathCchRemoveExtension)(WCHAR *path, SIZE_T size);
 HRESULT (WINAPI *pPathCchRenameExtension)(WCHAR *path, SIZE_T size, const WCHAR *extension);
 HRESULT (WINAPI *pPathCchSkipRoot)(const WCHAR *path, const WCHAR **root_end);
@@ -477,6 +478,72 @@ static void test_PathCchFindExtension(void)
     }
 }
 
+struct isroot_test
+{
+    const CHAR *path;
+    BOOL ret;
+};
+
+static const struct isroot_test isroot_tests[] =
+{
+    {"", FALSE},
+    {"a", FALSE},
+    {"C:", FALSE},
+    {"C:\\", TRUE},
+    {"C:\\a", FALSE},
+    {"\\\\?\\C:\\", TRUE},
+    {"\\\\?\\C:", FALSE},
+    {"\\\\?\\C:\\a", FALSE},
+    {"\\", TRUE},
+    {"\\a\\", FALSE},
+    {"\\a\\b", FALSE},
+    {"\\\\", TRUE},
+    {"\\\\a", TRUE},
+    {"\\\\a\\", FALSE},
+    {"\\\\a\\b", TRUE},
+    {"\\\\a\\b\\", FALSE},
+    {"\\\\a\\b\\c", FALSE},
+    {"\\\\?\\UNC\\", TRUE},
+    {"\\\\?\\UNC\\a", TRUE},
+    {"\\\\?\\UNC\\a\\", FALSE},
+    {"\\\\?\\UNC\\a\\b", TRUE},
+    {"\\\\?\\UNC\\a\\b\\", FALSE},
+    {"\\\\?\\UNC\\a\\b\\c", FALSE},
+    {"\\\\?\\Volume{e51a1864-6f2d-4019-b73d-f4e60e600c26}", FALSE},
+    {"\\\\?\\Volume{e51a1864-6f2d-4019-b73d-f4e60e600c26}\\", TRUE},
+    {"\\\\?\\Volume{e51a1864-6f2d-4019-b73d-f4e60e600c26}\\a", FALSE},
+    {"..\\a", FALSE},
+
+    /* Wrong MSDN examples */
+    {"\\a", FALSE},
+    {"X:", FALSE},
+    {"\\server", FALSE}
+};
+
+static void test_PathCchIsRoot(void)
+{
+    WCHAR pathW[MAX_PATH];
+    BOOL ret;
+    INT i;
+
+    if (!pPathCchIsRoot)
+    {
+        win_skip("PathCchIsRoot() is not available.\n");
+        return;
+    }
+
+    ret = pPathCchIsRoot(NULL);
+    ok(ret == FALSE, "expect return FALSE\n");
+
+    for (i = 0; i < ARRAY_SIZE(isroot_tests); i++)
+    {
+        const struct isroot_test *t = isroot_tests + i;
+        MultiByteToWideChar(CP_ACP, 0, t->path, -1, pathW, ARRAY_SIZE(pathW));
+        ret = pPathCchIsRoot(pathW);
+        ok(ret == t->ret, "path %s expect return %d, got %d\n", t->path, t->ret, ret);
+    }
+}
+
 struct removeextension_test
 {
     const CHAR *path;
@@ -1039,6 +1106,7 @@ START_TEST(path)
     pPathCchAddBackslashEx = (void *)GetProcAddress(hmod, "PathCchAddBackslashEx");
     pPathCchAddExtension = (void *)GetProcAddress(hmod, "PathCchAddExtension");
     pPathCchFindExtension = (void *)GetProcAddress(hmod, "PathCchFindExtension");
+    pPathCchIsRoot = (void *)GetProcAddress(hmod, "PathCchIsRoot");
     pPathCchRemoveExtension = (void *)GetProcAddress(hmod, "PathCchRemoveExtension");
     pPathCchRenameExtension = (void *)GetProcAddress(hmod, "PathCchRenameExtension");
     pPathCchSkipRoot = (void *)GetProcAddress(hmod, "PathCchSkipRoot");
@@ -1051,6 +1119,7 @@ START_TEST(path)
     test_PathCchAddBackslashEx();
     test_PathCchAddExtension();
     test_PathCchFindExtension();
+    test_PathCchIsRoot();
     test_PathCchRemoveExtension();
     test_PathCchRenameExtension();
     test_PathCchSkipRoot();
diff --git a/include/pathcch.h b/include/pathcch.h
index 56920b3444d..443ccd3a4f1 100644
--- a/include/pathcch.h
+++ b/include/pathcch.h
@@ -30,6 +30,7 @@ HRESULT WINAPI PathCchAddBackslashEx(WCHAR *path, SIZE_T size, WCHAR **end, SIZE
 HRESULT WINAPI PathCchAddExtension(WCHAR *path, SIZE_T size, const WCHAR *extension);
 HRESULT WINAPI PathCchCombineEx(WCHAR *out, SIZE_T size, const WCHAR *path1, const WCHAR *path2, DWORD flags);
 HRESULT WINAPI PathCchFindExtension(const WCHAR *path, SIZE_T size, const WCHAR **extension);
+BOOL    WINAPI PathCchIsRoot(const WCHAR *path);
 HRESULT WINAPI PathCchRemoveExtension(WCHAR *path, SIZE_T size);
 HRESULT WINAPI PathCchRenameExtension(WCHAR *path, SIZE_T size, const WCHAR *extension);
 HRESULT WINAPI PathCchSkipRoot(const WCHAR *path, const WCHAR **root_end);