diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index 0d53121..f03fe44 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -56,10 +56,17 @@
 " In the GUI we can always change the screen size.
 if has('gui_running')
   if has('gui_gtk')
-    " to keep screendump size unchanged
+    " Use e.g. SetUp() and TearDown() to change "&guifont" when needed;
+    " otherwise, keep the following value to match current screendumps.
     set guifont=Monospace\ 10
   endif
-  set columns=80 lines=25
+
+  func s:SetDefaultOptionsForGUIBuilds()
+    set columns=80 lines=25
+  endfunc
+else
+  func s:SetDefaultOptionsForGUIBuilds()
+  endfunc
 endif
 
 " Check that the screen size is at least 24 x 80 characters.
@@ -272,6 +279,9 @@
   " directory after executing the test.
   let save_cwd = getcwd()
 
+  " Permit "SetUp()" implementations to override default settings.
+  call s:SetDefaultOptionsForGUIBuilds()
+
   if exists("*SetUp")
     try
       call SetUp()
diff --git a/src/testdir/test_highlight.vim b/src/testdir/test_highlight.vim
index 5189b61..91423eb 100644
--- a/src/testdir/test_highlight.vim
+++ b/src/testdir/test_highlight.vim
@@ -1144,6 +1144,17 @@
 
 " Test for the hlset() function
 func Test_hlset()
+  " FIXME: With GVim, _current_ test cases that are run before this one may
+  "	influence the result of calling "hlset(hlget())", depending on what
+  "	"&guifont" is set to.  For example, introduce SetUp() as follows:
+  "
+  " if CanRunVimInTerminal() && has('gui_running') && has('gui_gtk')
+  "   def SetUp()
+  "     set guifont=Monospace\ 10
+  "   enddef
+  " endif
+  "
+  "	and see "E416: Missing equal sign: ... line 4" for this test case.
   let lines =<< trim END
     call assert_equal(0, hlset(test_null_list()))
     call assert_equal(0, hlset([]))
diff --git a/src/version.c b/src/version.c
index 3d83858..6896410 100644
--- a/src/version.c
+++ b/src/version.c
@@ -710,6 +710,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1438,
+/**/
     1437,
 /**/
     1436,