diff --git a/Lib/posixpath.py b/Lib/posixpath.py
index 667f5c5..e9f4251 100644
--- a/Lib/posixpath.py
+++ b/Lib/posixpath.py
@@ -200,6 +200,9 @@
 
 def ismount(path):
     """Test whether a path is a mount point"""
+    if islink(path):
+        # A symlink can never be a mount point
+        return False
     try:
         s1 = os.lstat(path)
         if isinstance(path, bytes):
diff --git a/Misc/NEWS b/Misc/NEWS
index 0fa7845..94bf2b9 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -29,6 +29,9 @@
 Library
 -------
 
+- Issue #1713: Fix os.path.ismount(), which returned true for symbolic links
+  across devices.
+
 - Issue #8826: Properly load old-style "expires" attribute in http.cookies.
 
 - Issue #1690103: Fix initial namespace for code run with trace.main().