diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt
index 0aede29d648991..5caa98e3fcc9b6 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -3,6 +3,9 @@ Released on 2019-12-16?
 ======================================
 
 
+bpo-38943: Fix autocomplete windows not always appearing on some
+systems.  Patch by Johnny Najera.
+
 bpo-38944: Excape key now closes IDLE completion windows.  Patch by
 Johnny Najera.
 
diff --git a/Lib/idlelib/autocomplete_w.py b/Lib/idlelib/autocomplete_w.py
index f20b6330997886..0643c092c6e548 100644
--- a/Lib/idlelib/autocomplete_w.py
+++ b/Lib/idlelib/autocomplete_w.py
@@ -257,6 +257,7 @@ def winconfig_event(self, event):
             # place acw above current line
             new_y -= acw_height
         acw.wm_geometry("+%d+%d" % (new_x, new_y))
+        acw.update_idletasks()
 
         if platform.system().startswith('Windows'):
             # See issue 15786. When on Windows platform, Tk will misbehave
diff --git a/Misc/NEWS.d/next/IDLE/2019-11-29-23-44-11.bpo-38943.8pUKKs.rst b/Misc/NEWS.d/next/IDLE/2019-11-29-23-44-11.bpo-38943.8pUKKs.rst
new file mode 100644
index 00000000000000..5c9323e2467876
--- /dev/null
+++ b/Misc/NEWS.d/next/IDLE/2019-11-29-23-44-11.bpo-38943.8pUKKs.rst
@@ -0,0 +1,2 @@
+Fix IDLE autocomplete windows not always appearing on some systems.
+Patch by Johnny Najera.