diff --git a/src/kernel_internals/typing/cabs2cil.ml b/src/kernel_internals/typing/cabs2cil.ml
index 000480d8dc808bd8737ae15fd25cd11940d13827..36f0167b48f18ce13b054dc6b766dca3975af7cb 100644
--- a/src/kernel_internals/typing/cabs2cil.ml
+++ b/src/kernel_internals/typing/cabs2cil.ml
@@ -1200,7 +1200,7 @@ let to_integer i =
     -1
 
 let constFoldToInteger e =
-  try Option.map Integer.to_int (Cil.constFoldToInt e)
+  try Option.map Integer.to_int_exn (Cil.constFoldToInt e)
   with Z.Overflow ->
     Kernel.error ~current:true
       "integer constant too large in expression %a"