diff --git a/ui-tui/src/__tests__/reasoning.test.ts b/ui-tui/src/__tests__/reasoning.test.ts
index d14a0a2975a..5d661e0059d 100644
--- a/ui-tui/src/__tests__/reasoning.test.ts
+++ b/ui-tui/src/__tests__/reasoning.test.ts
@@ -21,11 +21,26 @@ describe('splitReasoning', () => {
     expect(text).toBe('body')
   })
 
-  it('treats unclosed trailing <think>… as reasoning', () => {
-    const { reasoning, text } = splitReasoning('answer start <think>still deciding')
+  it('treats unclosed leading <think>… as reasoning (real reasoning-model stream)', () => {
+    const { reasoning, text } = splitReasoning('<think>still deciding')
 
     expect(reasoning).toBe('still deciding')
-    expect(text).toBe('answer start')
+    expect(text).toBe('')
+  })
+
+  it('does not strip trailing prose after a stray mid-text <think> mention', () => {
+    // Regression for "TUI eats last paragraph of output": when the model
+    // emits a literal `<think>` somewhere in prose (quoted explanation, code
+    // example, partial stream-mid-tag), the trailing greedy unclosed-tag
+    // regex used to consume every paragraph after it. Real unclosed
+    // reasoning blocks always lead the message — anchor to ^ so prose
+    // mentions are preserved.
+    const { reasoning, text } = splitReasoning(
+      'final answer paragraph one.\n\n<think>internal note never closed\n\nfinal answer paragraph two.'
+    )
+
+    expect(reasoning).toBe('')
+    expect(text).toBe('final answer paragraph one.\n\n<think>internal note never closed\n\nfinal answer paragraph two.')
   })
 
   it('returns empty reasoning and untouched text when no tags present', () => {
diff --git a/ui-tui/src/lib/reasoning.ts b/ui-tui/src/lib/reasoning.ts
index eba63918c41..d80260dbd4f 100644
--- a/ui-tui/src/lib/reasoning.ts
+++ b/ui-tui/src/lib/reasoning.ts
@@ -21,7 +21,12 @@ export function splitReasoning(input: string): SplitReasoning {
       return ''
     })
 
-    const unclosed = new RegExp(`<${tag}>([\\s\\S]*)$`, 'i')
+    // Anchor to start-of-input so a literal `<think>` mid-prose (model quoting
+    // the word, code blocks containing the tag, etc.) doesn't eat every
+    // paragraph after it. Real unclosed reasoning blocks always lead the
+    // message — that's how reasoning models stream. See test
+    // "does not strip trailing prose after a stray mid-text <think> mention".
+    const unclosed = new RegExp(`^\\s*<${tag}>([\\s\\S]*)$`, 'i')
     text = text.replace(unclosed, (_m, inner: string) => {
       const trimmed = inner.trim()