diff --git a/vncviewer/Viewport.cxx b/vncviewer/Viewport.cxx
index 917a981..81dc7ac 100644
--- a/vncviewer/Viewport.cxx
+++ b/vncviewer/Viewport.cxx
@@ -410,6 +410,7 @@
     return 1;
 
   case FL_FOCUS:
+    Fl::disable_im();
     // Yes, we would like some focus please!
     return 1;
 
@@ -418,6 +419,7 @@
     // sense (e.g. Alt+Tab where we only see the Alt press)
     while (!downKeySym.empty())
       handleKeyRelease(downKeySym.begin()->first);
+    Fl::enable_im();
     return 1;
 
   case FL_KEYDOWN: