diff --git a/kernel/acct.c b/kernel/acct.c
index f175df8f6aa4..12f7dacf560e 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -331,6 +331,8 @@ static comp_t encode_comp_t(unsigned long value)
 		exp++;
 	}
 
+	if (exp > (((comp_t) ~0U) >> MANTSIZE))
+		return (comp_t) ~0U;
 	/*
 	 * Clean it up and polish it off.
 	 */