diff --git a/packages/tui/src/terminal.ts b/packages/tui/src/terminal.ts
index d0e48aa92..4616d14b7 100644
--- a/packages/tui/src/terminal.ts
+++ b/packages/tui/src/terminal.ts
@@ -312,6 +312,7 @@ export function emergencyTerminalRestore(): void {
 			process.stdout.write(
 				"\x1b[?2026l" + // End synchronized output
 					"\x1b[?7h" + // Restore autowrap
+					"\x1b[?1l\x1b>" + // Restore normal cursor-key + keypad mode (rmkx, #6374)
 					"\x1b[?2004l" + // Disable bracketed paste
 					"\x1b[?2031l" + // Disable Mode 2031 appearance notifications
 					"\x1b[?2048l" + // Disable in-band resize notifications
@@ -625,6 +626,15 @@ export class ProcessTerminal implements Terminal {
 		// Enable bracketed paste mode - terminal will wrap pastes in \x1b[200~ ... \x1b[201~
 		this.#safeWrite("\x1b[?2004h");
 
+		// Force normal cursor-key (DECCKM) and numeric-keypad mode (terminfo
+		// `rmkx` = "\x1b[?1l\x1b>"). omp decodes both CSI ("\x1b[A") and SS3
+		// ("\x1bOA") arrow encodings, so it never enables application mode
+		// itself — but a prior program that left the TTY in application-cursor-
+		// keys mode makes arrows arrive as SS3. Normalizing on entry keeps input
+		// in the predictable default state; stop() restores the same on exit.
+		// See #6374.
+		this.#safeWrite("\x1b[?1l\x1b>");
+
 		// Set up resize handler immediately. The OS refreshes process.stdout
 		// dimensions before firing `resize`, so it is authoritative for geometry:
 		// reconcile any stale cached DEC 2048 report before notifying the renderer.
@@ -1376,6 +1386,13 @@ export class ProcessTerminal implements Terminal {
 		// begin/end halves of a frame. Safe no-ops on terminals that ignored them.
 		this.#safeWrite("\x1b[?2026l\x1b[?7h");
 
+		// Restore normal cursor-key (DECCKM) and numeric-keypad mode (terminfo
+		// `rmkx`). Symmetric with the normalize in start(): a TTY-sharing child
+		// can leave the terminal in application-cursor-keys mode, and without
+		// this reset the parent shell inherits SS3 arrows so Up/Down history
+		// navigation stays broken after omp exits (#6374).
+		this.#safeWrite("\x1b[?1l\x1b>");
+
 		// Disable bracketed paste mode
 		this.#safeWrite("\x1b[?2004l");
 		this.#safeWrite("\x1b[?5522l");
diff --git a/packages/tui/test/process-terminal-headless.test.ts b/packages/tui/test/process-terminal-headless.test.ts
index d7acd9126..34f925a3a 100644
--- a/packages/tui/test/process-terminal-headless.test.ts
+++ b/packages/tui/test/process-terminal-headless.test.ts
@@ -93,4 +93,30 @@ describe("ProcessTerminal headless suppression", () => {
 			setTerminalHeadless(previous);
 		}
 	});
+
+	// #6374: arrows stopped working inside omp and stayed broken in the shell
+	// after exit — a missing cursor-key/keypad reset. omp owns the TTY and emits
+	// a full private-mode reset menu, but never restored normal cursor-key
+	// (DECCKM) / numeric-keypad mode (terminfo `rmkx` = "\x1b[?1l\x1b>"). If the
+	// terminal was left in application-cursor-keys mode, arrows arrived as SS3
+	// and the parent shell's Up/Down history navigation broke. start() must
+	// normalize the state and stop() must restore it.
+	it("emits rmkx on start and stop to normalize/restore cursor-key + keypad mode (#6374)", () => {
+		const previous = setTerminalHeadless(false);
+		const terminal = new ProcessTerminal();
+		try {
+			terminal.start(
+				() => {},
+				() => {},
+			);
+			expect(writes.join("")).toContain("\x1b[?1l\x1b>");
+
+			writes.length = 0;
+			terminal.stop();
+			expect(writes.join("")).toContain("\x1b[?1l\x1b>");
+		} finally {
+			terminal.stop();
+			setTerminalHeadless(previous);
+		}
+	});
 });