diff --git a/kernel/acct.c b/kernel/acct.c
index 31b09cf7189c..010667ce6080 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -350,6 +350,8 @@ static comp_t encode_comp_t(u64 value)
 		exp++;
 	}
 
+	if (exp > (((comp_t) ~0U) >> MANTSIZE))
+		return (comp_t) ~0U;
 	/*
 	 * Clean it up and polish it off.
 	 */