diff --git a/lib/div64.c b/lib/div64.c
index 01c8602..ee146bb 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -109,7 +109,7 @@ u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
 		quot = div_u64_rem(dividend, divisor, &rem32);
 		*remainder = rem32;
 	} else {
-		int n = 1 + fls(high);
+		int n = fls(high);
 		quot = div_u64(dividend >> n, divisor >> n);
 
 		if (quot != 0)
@@ -147,7 +147,7 @@ u64 div64_u64(u64 dividend, u64 divisor)
 	if (high == 0) {
 		quot = div_u64(dividend, divisor);
 	} else {
-		int n = 1 + fls(high);
+		int n = fls(high);
 		quot = div_u64(dividend >> n, divisor >> n);
 
 		if (quot != 0)