diff --git a/backend/plugins/github/tasks/issue_extractor.go b/backend/plugins/github/tasks/issue_extractor.go
index 2f7771216f5..2f80c928617 100644
--- a/backend/plugins/github/tasks/issue_extractor.go
+++ b/backend/plugins/github/tasks/issue_extractor.go
@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"regexp"
 	"strings"
+	"time"
 
 	"github.com/apache/devlake/core/dal"
 	"github.com/apache/devlake/core/errors"
@@ -203,8 +204,7 @@ func convertGithubIssue(issue *IssuesResponse, connectionId uint64, repositoryId
 		githubIssue.AuthorName = issue.User.Login
 	}
 	if issue.ClosedAt != nil {
-		temp := uint(issue.ClosedAt.ToTime().Sub(issue.GithubCreatedAt.ToTime()).Minutes())
-		githubIssue.LeadTimeMinutes = &temp
+		githubIssue.LeadTimeMinutes = IssueLeadTimeMinutes(issue.GithubCreatedAt.ToTime(), issue.ClosedAt.ToTime())
 	}
 	if issue.Milestone != nil {
 		githubIssue.MilestoneId = issue.Milestone.Id
@@ -212,6 +212,19 @@ func convertGithubIssue(issue *IssuesResponse, connectionId uint64, repositoryId
 	return githubIssue, nil
 }
 
+// IssueLeadTimeMinutes returns the minutes from creation to close.
+// GitHub can report a close time before the creation time, for example for an
+// issue that was closed and then transferred from another repository. A negative
+// duration cast to uint wraps to a huge value that the domain issues table rejects,
+// which fails the whole Convert Issues subtask, so leave lead time unset instead.
+func IssueLeadTimeMinutes(createdAt, closedAt time.Time) *uint {
+	if closedAt.Before(createdAt) {
+		return nil
+	}
+	minutes := uint(closedAt.Sub(createdAt).Minutes())
+	return &minutes
+}
+
 func convertGithubLabels(issueRegexes *IssueRegexes, issue *IssuesResponse, githubIssue *models.GithubIssue) ([]interface{}, errors.Error) {
 	var results []interface{}
 	var joinedLabels []string
diff --git a/backend/plugins/github/tasks/issue_extractor_test.go b/backend/plugins/github/tasks/issue_extractor_test.go
new file mode 100644
index 00000000000..b8294240ace
--- /dev/null
+++ b/backend/plugins/github/tasks/issue_extractor_test.go
@@ -0,0 +1,42 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package tasks
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIssueLeadTimeMinutes(t *testing.T) {
+	createdAt := time.Date(2026, 11, 1, 9, 49, 53, 0, time.UTC)
+
+	leadTime := IssueLeadTimeMinutes(createdAt, createdAt.Add(90*time.Minute))
+	if assert.NotNil(t, leadTime) {
+		assert.Equal(t, uint(90), *leadTime)
+	}
+
+	leadTime = IssueLeadTimeMinutes(createdAt, createdAt)
+	if assert.NotNil(t, leadTime) {
+		assert.Equal(t, uint(0), *leadTime)
+	}
+
+	// Closed before created, as GitHub reports for some transferred issues.
+	assert.Nil(t, IssueLeadTimeMinutes(createdAt, createdAt.Add(-44*time.Minute)))
+}
diff --git a/backend/plugins/github_graphql/tasks/issue_extractor.go b/backend/plugins/github_graphql/tasks/issue_extractor.go
index 345b6fcfb59..3f15bd0d949 100644
--- a/backend/plugins/github_graphql/tasks/issue_extractor.go
+++ b/backend/plugins/github_graphql/tasks/issue_extractor.go
@@ -152,8 +152,7 @@ func convertGithubIssue(milestoneMap map[int]int, issue *GraphqlQueryIssue, conn
 		githubIssue.AuthorName = author.Login
 	}
 	if issue.ClosedAt != nil {
-		temp := uint(issue.ClosedAt.Sub(issue.CreatedAt).Minutes())
-		githubIssue.LeadTimeMinutes = &temp
+		githubIssue.LeadTimeMinutes = githubTasks.IssueLeadTimeMinutes(issue.CreatedAt, *issue.ClosedAt)
 	}
 	if issue.Milestone != nil {
 		if milestoneId, ok := milestoneMap[issue.Milestone.Number]; ok {