diff --git a/internal/tui/app.go b/internal/tui/app.go
index c033ca2..af21868 100644
--- a/internal/tui/app.go
+++ b/internal/tui/app.go
@@ -342,6 +342,7 @@ type App struct {
 	sessRefsCursor        int                   // cursor within the References preview list
 	sessRefsResolved      bool                  // whether the currently-previewed session's refs have been resolved
 	refsInFlight          map[string]bool       // session IDs with a resolve pass currently running (prevents re-targeting every tick)
+	openURL               func(string) error    // opens a URL in the browser; overridable in tests (defaults to `open`)
 
 	// Conversation preview state
 	sessConvEntries     []mergedMsg     // merged conversation messages
@@ -1807,6 +1808,13 @@ func (a *App) handleSessionKeys(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			m, cmd, _ := a.drillIntoWorkflowAgent()
 			return m, cmd
 		}
+		// If References preview is focused, open the PR/Jira URL under the cursor
+		// in the browser (mirrors `o`; without this Enter would fall through to
+		// openConversation).
+		if sp.Focus && sp.Show && a.sessPreviewMode == sessPreviewRefs && len(a.sessPreviewRefs) > 0 {
+			m, cmd, _ := a.openRefUnderCursor()
+			return m, cmd
+		}
 		sess, ok := a.selectedSession()
 		if !ok {
 			return a, nil
@@ -2278,7 +2286,7 @@ func (a *App) openRefUnderCursor() (tea.Model, tea.Cmd, bool) {
 		a.copiedMsg = "No URL for this reference"
 		return a, nil, true
 	}
-	if err := exec.Command("open", ref.URL).Start(); err != nil {
+	if err := a.openInBrowser(ref.URL); err != nil {
 		a.copiedMsg = "Error: " + err.Error()
 		return a, nil, true
 	}
@@ -2286,6 +2294,15 @@ func (a *App) openRefUnderCursor() (tea.Model, tea.Cmd, bool) {
 	return a, nil, true
 }
 
+// openInBrowser opens a URL in the default browser. The opener is overridable
+// (a.openURL) so tests can intercept it instead of spawning `open`.
+func (a *App) openInBrowser(url string) error {
+	if a.openURL != nil {
+		return a.openURL(url)
+	}
+	return exec.Command("open", url).Start()
+}
+
 // drillIntoWorkflowAgent opens the conversation view for the current session and
 // navigates into the workflow agent under the cursor — its full transcript,
 // which the workflow run summary only previews.
diff --git a/internal/tui/refs_preview_test.go b/internal/tui/refs_preview_test.go
index dbcf185..02818d9 100644
--- a/internal/tui/refs_preview_test.go
+++ b/internal/tui/refs_preview_test.go
@@ -90,3 +90,42 @@ func TestRenderSessionRefs(t *testing.T) {
 		t.Error("focused render missing open hint")
 	}
 }
+
+// TestRefsPreviewEnterOpensURL guards the reported bug: with the References
+// preview focused, Enter on a PR/Jira entry must open its URL in the browser —
+// NOT fall through to km.Session.Open and open the conversation. `o` already
+// worked; Enter was intercepted by the Session.Open case, which had no refs
+// branch. Both Enter and `o` must open the URL and leave the view unchanged.
+func TestRefsPreviewEnterOpensURL(t *testing.T) {
+	for _, key := range []tea.KeyMsg{
+		{Type: tea.KeyEnter},
+		{Type: tea.KeyRunes, Runes: []rune{'o'}},
+	} {
+		sessions := fakeSessions()
+		a := newTestApp(sessions)
+		a.sessionList.Select(0)
+
+		// Simulate a focused, populated References preview.
+		a.sessPreviewMode = sessPreviewRefs
+		a.sessSplit.Show = true
+		a.sessSplit.Focus = true
+		a.sessPreviewRefs = []session.SessionRef{
+			{Kind: session.RefPR, URL: "https://github.com/sendbird/ccx/pull/62",
+				Label: "sendbird/ccx#62", State: session.RefStateOpen, Resolved: true},
+		}
+		a.sessRefsCursor = 0
+
+		var opened string
+		a.openURL = func(u string) error { opened = u; return nil }
+
+		m, _ := a.Update(key)
+		got := m.(*App)
+
+		if opened != "https://github.com/sendbird/ccx/pull/62" {
+			t.Errorf("key %v: expected the ref URL to be opened, got %q", key, opened)
+		}
+		if got.state != viewSessions {
+			t.Errorf("key %v: view changed to %v — Enter leaked to openConversation", key, got.state)
+		}
+	}
+}