diff --git a/datetime/datetime.go b/datetime/datetime.go
index ebb92bc..60ae892 100644
--- a/datetime/datetime.go
+++ b/datetime/datetime.go
@@ -75,8 +75,12 @@ func (dt datetime) add(y, m, d, h, i int, e ...int) datetime {
 			p, v = PrecisionMillisecond, v+e[1]
 		}
 	}
-	dc := v / MillisecondPerDay
-	d, v = d+dc, v-dc*MillisecondPerDay
+	d += v / MillisecondPerDay
+	v %= MillisecondPerDay
+	if v < 0 {
+		d--
+		v += MillisecondPerDay
+	}
 	return newDT(dt.date.add(y, m, d), newC(uint(v), p))
 }
 func (dt datetime) addT(y, m, d int) datetime        { return newDT(dt.date.add(y, m, d), dt.clock) }
diff --git a/go.mod b/go.mod
index 184b15e..f0b8f27 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,5 @@
 module gitea.zaclys.com/bvaudour/gob
 
-go 1.21
+go 1.22
 
-require golang.org/x/crypto v0.13.0
+require golang.org/x/crypto v0.19.0
diff --git a/go.sum b/go.sum
index 8886ba7..b3dc059 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,2 @@
-golang.org/x/crypto v0.13.0 h1:mvySKfSWJ+UKUii46M40LOvyWfN0s2U+46/jDd0e6Ck=
-golang.org/x/crypto v0.13.0/go.mod h1:y6Z2r+Rw4iayiXXAIxJIDAJ1zMW4yaTpebo8fPOliYc=
+golang.org/x/crypto v0.19.0 h1:ENy+Az/9Y1vSrlrvBSyna3PITt4tiZLf7sgCjZBX7Wo=
+golang.org/x/crypto v0.19.0/go.mod h1:Iy9bg/ha4yyC70EfRS8jz+B6ybOBKMaSxLj6P6oBDfU=