diff --git a/cmd/admin-handlers-users.go b/cmd/admin-handlers-users.go
index 8a88094fd..8488a95ba 100644
--- a/cmd/admin-handlers-users.go
+++ b/cmd/admin-handlers-users.go
@@ -830,7 +830,11 @@ func (a adminAPIHandlers) UpdateServiceAccount(w http.ResponseWriter, r *http.Re
 	}
 
 	condValues := getConditionValues(r, "", cred)
-	addExpirationToCondValues(updateReq.NewExpiration, condValues)
+	err = addExpirationToCondValues(updateReq.NewExpiration, condValues)
+	if err != nil {
+		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
+		return
+	}
 
 	// Permission checks:
 	//
@@ -2459,11 +2463,16 @@ func (a adminAPIHandlers) ImportIAM(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
-func addExpirationToCondValues(exp *time.Time, condValues map[string][]string) {
-	if exp == nil {
-		return
+func addExpirationToCondValues(exp *time.Time, condValues map[string][]string) error {
+	if exp == nil || exp.IsZero() || exp.Equal(timeSentinel) {
+		return nil
 	}
-	condValues["DurationSeconds"] = []string{strconv.FormatInt(int64(exp.Sub(time.Now()).Seconds()), 10)}
+	dur := exp.Sub(time.Now())
+	if dur <= 0 {
+		return errors.New("unsupported expiration time")
+	}
+	condValues["DurationSeconds"] = []string{strconv.FormatInt(int64(dur.Seconds()), 10)}
+	return nil
 }
 
 func commonAddServiceAccount(r *http.Request) (context.Context, auth.Credentials, newServiceAccountOpts, madmin.AddServiceAccountReq, string, APIError) {
@@ -2528,7 +2537,10 @@ func commonAddServiceAccount(r *http.Request) (context.Context, auth.Credentials
 	}
 
 	condValues := getConditionValues(r, "", cred)
-	addExpirationToCondValues(createReq.Expiration, condValues)
+	err = addExpirationToCondValues(createReq.Expiration, condValues)
+	if err != nil {
+		return ctx, auth.Credentials{}, newServiceAccountOpts{}, madmin.AddServiceAccountReq{}, "", toAdminAPIErr(ctx, err)
+	}
 
 	// Check if action is allowed if creating access key for another user
 	// Check if action is explicitly denied if for self