diff --git a/examples/pdf-attach-file.cc b/examples/pdf-attach-file.cc
index 903f30eb..0c046000 100644
--- a/examples/pdf-attach-file.cc
+++ b/examples/pdf-attach-file.cc
@@ -60,16 +60,7 @@ static void process(char const* infilename, char const* password,
             ">>"));
 
     // Create a file spec.
-    std::string key(attachment);
-    size_t pos = key.find_last_of("/\\");
-    if (pos != std::string::npos)
-    {
-        key = key.substr(pos + 1);
-    }
-    if (key.empty())
-    {
-        throw std::runtime_error("can't get last path element of attachment");
-    }
+    std::string key = QUtil::path_basename(attachment);
     std::cout << whoami << ": attaching " << attachment << " as " << key
               << std::endl;
     auto fs = QPDFFileSpecObjectHelper::createFileSpec(q, key, attachment);
diff --git a/qpdf/qpdf.cc b/qpdf/qpdf.cc
index 8de2ab8b..0c0b344f 100644
--- a/qpdf/qpdf.cc
+++ b/qpdf/qpdf.cc
@@ -2873,16 +2873,10 @@ ArgParser::argEndAddAttachment()
     {
         usage("add attachment: no path specified");
     }
-    std::string last_element = cur.path;
-    size_t pathsep = cur.path.find_last_of("/\\");
-    if (pathsep != std::string::npos)
+    std::string last_element = QUtil::path_basename(cur.path);
+    if (last_element.empty())
     {
-        last_element = cur.path.substr(pathsep + 1);
-        if (last_element.empty())
-        {
-            usage("path for --add-attachment may not end"
-                  " with a path separator");
-        }
+        usage("path for --add-attachment may not be empty");
     }
     if (cur.filename.empty())
     {
diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index c033e7ef..4ed3ac33 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -523,7 +523,7 @@ $td->runtest("page operations on form xobject",
 show_ntests();
 # ----------
 $td->notify("--- File Attachments ---");
-$n_tests += 34;
+$n_tests += 33;
 
 open(F, ">auto-txt") or die;
 print F "from file";
@@ -596,12 +596,6 @@ $td->runtest("add attachment: bad mod date",
                   ".*mime type should be specified as type/subtype.*",
                   $td->EXIT_STATUS => 2},
 	     $td->NORMALIZE_NEWLINES);
-$td->runtest("add attachment: trailing slash",
-	     {$td->COMMAND => "qpdf minimal.pdf a.pdf" .
-                  " --add-attachment auto-txt/ --"},
-	     {$td->REGEXP => ".*may not end with a path separator.*",
-                  $td->EXIT_STATUS => 2},
-	     $td->NORMALIZE_NEWLINES);
 $td->runtest("add attachment: trailing slash",
 	     {$td->COMMAND => "qpdf minimal.pdf a.pdf" .
                   " --add-attachment --"},