diff --git a/Sources/ProGhosttyCore/TerminalCore/PTY/PTYTerminalEngine.swift b/Sources/ProGhosttyCore/TerminalCore/PTY/PTYTerminalEngine.swift
index 7712888..4fead60 100644
--- a/Sources/ProGhosttyCore/TerminalCore/PTY/PTYTerminalEngine.swift
+++ b/Sources/ProGhosttyCore/TerminalCore/PTY/PTYTerminalEngine.swift
@@ -48,7 +48,7 @@ func terminalControlInputData(for event: NSEvent) -> Data? {
     case UInt32(NSEnterCharacter), UInt32(NSCarriageReturnCharacter):
       return event.modifierFlags.contains(.shift) ? Data([0x0A]) : Data([0x0D])
     case UInt32(NSTabCharacter):
-      return Data([0x09])
+      return event.modifierFlags.contains(.shift) ? Data("\u{1B}[Z".utf8) : Data([0x09])
     case UInt32(NSBackspaceCharacter):
       return Data([0x7F])
     case 0x1B:
diff --git a/Tests/ProGhosttyCoreTests/PTYLaunchTests.swift b/Tests/ProGhosttyCoreTests/PTYLaunchTests.swift
index 028a093..0900d15 100644
--- a/Tests/ProGhosttyCoreTests/PTYLaunchTests.swift
+++ b/Tests/ProGhosttyCoreTests/PTYLaunchTests.swift
@@ -29,6 +29,17 @@ struct PTYLaunchTests {
     #expect(terminalControlInputData(for: event) == Data([0x0D]))
   }
 
+  @Test func shiftTabProducesBackTabSequence() throws {
+    let event = try #require(makeKeyEvent(
+      keyCode: 48,
+      characters: "\t",
+      charactersIgnoringModifiers: "\t",
+      modifierFlags: [.shift]
+    ))
+
+    #expect(terminalControlInputData(for: event) == Data("\u{1B}[Z".utf8))
+  }
+
   @Test func shellArgumentsUseShellBasename() {
     #expect(PTYLaunch.shellArguments(shellPath: "/bin/zsh") == ["zsh"])
   }