diff --git a/src/lread.c b/src/lread.c
index 6eda7405409..9ddd8d5a7f6 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -3797,7 +3797,12 @@ string_to_number (char const *string, int base, int flags)
 	value = n;
 
       if (! (state & DOT_CHAR) && ! (flags & S2N_OVERFLOW_TO_FLOAT))
-	xsignal1 (Qoverflow_error, build_string (string));
+	{
+	  AUTO_STRING (fmt, ("%s is out of fixnum range; "
+			     "maybe set `read-integer-overflow-as-float'?"));
+	  AUTO_STRING_WITH_LEN (arg, string, cp - string);
+	  xsignal1 (Qoverflow_error, CALLN (Fformat_message, fmt, arg));
+	}
     }
 
   /* Either the number uses float syntax, or it does not fit into a fixnum.