diff --git a/Tusker/Screens/Compose/ComposeContentWarningTextField.swift b/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
index 70059cee..973ccd59 100644
--- a/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
+++ b/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
@@ -147,6 +147,10 @@ struct ComposeContentWarningTextField: UIViewRepresentable {
             let selectedRangeStartUTF16 = textField.offset(from: textField.beginningOfDocument, to: selectedRange.start)
             let cursorIndex = text.utf16.index(text.startIndex, offsetBy: selectedRangeStartUTF16)
             
+            guard cursorIndex != text.startIndex else {
+                return nil
+            }
+            
             var lastWordStartIndex = text.index(before: cursorIndex)
             while true {
                 let c = text[lastWordStartIndex]