diff --git a/setup/extensions.json b/setup/extensions.json
index 2c9d5187de..4638e5046c 100644
--- a/setup/extensions.json
+++ b/setup/extensions.json
@@ -141,7 +141,7 @@
         "only": "windows",
         "headers": "calibre/utils/windows/common.h",
         "sources": "calibre/utils/windows/winutil.cpp",
-        "libraries": "shell32 wininet advapi32",
+        "libraries": "shell32 wininet advapi32 Pathcch",
         "cflags": "/X"
     },
     {
diff --git a/src/calibre/utils/windows/winutil.cpp b/src/calibre/utils/windows/winutil.cpp
index 125cdd5e85..17fa709359 100644
--- a/src/calibre/utils/windows/winutil.cpp
+++ b/src/calibre/utils/windows/winutil.cpp
@@ -15,6 +15,7 @@
 #include <shlguid.h>
 #include <shellapi.h>
 #include <shlwapi.h>
+#include <pathcch.h>
 #include <commoncontrols.h>
 #include <comip.h>
 #include <comdef.h>
@@ -724,6 +725,24 @@ get_long_path_name(PyObject *self, PyObject *args) {
     return ans;
 }
 
+static PyObject *
+canonicalize_path(PyObject *self, PyObject *args) {
+    wchar_raii path;
+    if (!PyArg_ParseTuple(args, "O&", py_to_wchar_no_none, &path)) return NULL;
+	size_t path_len = 0;
+	wchar_t *p = path.ptr();
+	while (p[path_len]) {
+		if (p[path_len] == '/') p[path_len] = '\\';
+		path_len++;
+	}
+	wchar_t *ans;
+	HRESULT hr = PathAllocCanonicalize(p, PATHCCH_ENSURE_IS_EXTENDED_LENGTH_PATH, &ans);
+	if (FAILED(hr)) return error_from_hresult(hr, "Failed to canonicalize path", PyTuple_GET_ITEM(args, 0));
+	PyObject *r = PyUnicode_FromWideChar(ans, -1);
+	LocalFree(ans);
+	return r;
+}
+
 static PyObject *
 get_process_times(PyObject *self, PyObject *pid) {
     HANDLE h = INVALID_HANDLE_VALUE;
@@ -1006,6 +1025,7 @@ static PyMethodDef winutil_methods[] = {
     M(set_handle_information, METH_VARARGS),
     M(get_long_path_name, METH_VARARGS),
     M(get_process_times, METH_O),
+    M(canonicalize_path, METH_VARARGS),
 	M(get_handle_information, METH_VARARGS),
 	M(get_last_error, METH_NOARGS),
 	M(load_library, METH_VARARGS),