diff --git a/lisp/international/iso-acc.el b/lisp/international/iso-acc.el
index 468de118dd8..68c9ca58a8c 100644
--- a/lisp/international/iso-acc.el
+++ b/lisp/international/iso-acc.el
@@ -129,6 +129,8 @@
     ((?\~ ?t) ?\376)
     ((?\~ ?>) ?\273)
     ((?\~ ?<) ?\253)
+    ((?\~ ?!) ?\241)  ;; Inverted exclamation mark
+    ((?\~ ??) ?\277)  ;; Inverted question mark
     ((?\~ ?\ ) ?\~)
     ((?\~ ?\~) ?\270) ;; cedilla accent
     ((?\/ ?A) ?\305) ;; A-with-ring (Norwegian and Danish)