diff --git a/interface/wx/filename.h b/interface/wx/filename.h
index d8ffcb16e7..a24ee7873d 100644
--- a/interface/wx/filename.h
+++ b/interface/wx/filename.h
@@ -877,6 +877,14 @@ public:
 
     /**
         Returns the string separating the volume from the path for this format.
+
+        Note that for @c wxPATH_DOS paths this string can only be used for
+        single-character volumes representing the drive letters, but not with
+        the UNC or GUID volumes (see their description in GetVolume()
+        documentation). For this reason, its use should be avoided, prefer
+        using wxFileName constructor and Assign() overload taking the volume
+        and the path as separate arguments to combining the volume and the path
+        into a single string using the volume separator between them.
     */
     static wxString GetVolumeSeparator(wxPathFormat format = wxPATH_NATIVE);
 
diff --git a/tests/filename/filenametest.cpp b/tests/filename/filenametest.cpp
index bebda4e250..c38c9fa442 100644
--- a/tests/filename/filenametest.cpp
+++ b/tests/filename/filenametest.cpp
@@ -169,7 +169,9 @@ TEST_CASE("wxFileName::Construction", "[filename]")
         // if the test is run from root directory or its direct subdirectory
         CHECK( fn.Normalize(wxPATH_NORM_ALL, "/foo/bar/baz", fni.format) );
 
-        if ( *fni.volume && *fni.path )
+        // restrict this check to drive letter volumes as UNC and GUID volumes
+        // can't be combined with the path using the volume separator
+        if ( strlen(fni.volume) == 1 && *fni.path )
         {
             // check that specifying the volume separately or as part of the
             // path doesn't make any difference