diff --git a/modules/structs/issue_milestone.go b/modules/structs/issue_milestone.go
index 5932ffdedcb..8acb94c3a2c 100644
--- a/modules/structs/issue_milestone.go
+++ b/modules/structs/issue_milestone.go
@@ -58,5 +58,5 @@ type EditMilestoneOption struct {
 	State *string `json:"state"`
 	// Deadline is the due date for the milestone, use null or empty string to remove the deadline
 	// swagger:strfmt date-time
-	Deadline optional.Option[*string] `json:"due_on,omitzero"`
+	Deadline optional.Option[*string] `json:"due_on,omitzero" form:"-"` // go-chi/binding panics validating the nil element a JSON null decodes to
 }
diff --git a/tests/integration/api_issue_milestone_test.go b/tests/integration/api_issue_milestone_test.go
index cb3f87072fd..8a49a7649c6 100644
--- a/tests/integration/api_issue_milestone_test.go
+++ b/tests/integration/api_issue_milestone_test.go
@@ -49,9 +49,11 @@ func TestAPIIssuesMilestone(t *testing.T) {
 	apiMilestone2 := DecodeJSON(t, resp, &structs.Milestone{})
 	assert.EqualValues(t, "closed", apiMilestone2.State)
 
-	req = NewRequestWithJSON(t, "PATCH", urlStr, map[string]any{"due_on": ""}).AddTokenAuth(token)
-	resp = MakeRequest(t, req, http.StatusOK)
-	assert.Nil(t, DecodeJSON(t, resp, &structs.Milestone{}).Deadline)
+	for _, dueOn := range []any{"", nil} {
+		req = NewRequestWithJSON(t, "PATCH", urlStr, map[string]any{"due_on": dueOn}).AddTokenAuth(token)
+		resp = MakeRequest(t, req, http.StatusOK)
+		assert.Nil(t, DecodeJSON(t, resp, &structs.Milestone{}).Deadline)
+	}
 
 	req = NewRequestWithJSON(t, "POST", fmt.Sprintf("/api/v1/repos/%s/%s/milestones", owner.Name, repo.Name), structs.CreateMilestoneOption{
 		Title:       "wow",