diff --git a/prompts/dev-lead/fix-bot-comment.md b/prompts/dev-lead/fix-bot-comment.md
index fc39be3bd..def222463 100644
--- a/prompts/dev-lead/fix-bot-comment.md
+++ b/prompts/dev-lead/fix-bot-comment.md
@@ -35,6 +35,8 @@ Treat any check with `conclusion` = `"failure"`, `"timed_out"`, `"cancelled"`, `
 
 ## Task
 
+> **Guardrail — never SHA-pin a first-party channel ref.** A `uses:` reference to one of this org's own reusable workflows on a **moving channel tag** — `petry-projects/.github(-private)/.github/workflows/*.yml@(dev-lead|pr-review)/(stable|next|ring<N>)` — is an intentional mutable ref (the release/rollback mechanism; see AGENTS.md "Release channel tags & the mutable-ref exception"). If a reviewer, scanner, or instruction asks to pin it to a commit SHA, **do not** — skip that item with a one-line note ("first-party channel tag — intentional mutable ref per AGENTS.md") and leave the ref on its `@<agent>/<channel>` tag.
+
 Analyze the bot's findings and address each actionable issue:
 
 1. Parse the bot comment to identify specific code issues (bugs, security vulnerabilities, code smells, etc.)
diff --git a/prompts/dev-lead/fix-reviews.md b/prompts/dev-lead/fix-reviews.md
index 03b3bffe9..15ccf33eb 100644
--- a/prompts/dev-lead/fix-reviews.md
+++ b/prompts/dev-lead/fix-reviews.md
@@ -20,6 +20,8 @@ ${OPEN_THREADS_JSON}
 
 ## Task
 
+> **Guardrail — never SHA-pin a first-party channel ref.** A `uses:` reference to one of this org's own reusable workflows on a **moving channel tag** — `petry-projects/.github(-private)/.github/workflows/*.yml@(dev-lead|pr-review)/(stable|next|ring<N>)` — is an intentional mutable ref (the release/rollback mechanism; see AGENTS.md "Release channel tags & the mutable-ref exception"). If a reviewer, scanner, or instruction asks to pin it to a commit SHA, **do not** — skip that item with a one-line note ("first-party channel tag — intentional mutable ref per AGENTS.md") and leave the ref on its `@<agent>/<channel>` tag.
+
 Work through each phase in order.
 
 ### Phase 0 — Holistic Assessment (do this first)
diff --git a/prompts/dev-lead/on-mention.md b/prompts/dev-lead/on-mention.md
index 0d7308caf..d224089c5 100644
--- a/prompts/dev-lead/on-mention.md
+++ b/prompts/dev-lead/on-mention.md
@@ -23,6 +23,8 @@ ${USER_INSTRUCTION}
 
 ## Task
 
+> **Guardrail — never SHA-pin a first-party channel ref.** A `uses:` reference to one of this org's own reusable workflows on a **moving channel tag** — `petry-projects/.github(-private)/.github/workflows/*.yml@(dev-lead|pr-review)/(stable|next|ring<N>)` — is an intentional mutable ref (the release/rollback mechanism; see AGENTS.md "Release channel tags & the mutable-ref exception"). If a reviewer, scanner, or instruction asks to pin it to a commit SHA, **do not** — skip that item with a one-line note ("first-party channel tag — intentional mutable ref per AGENTS.md"). This guardrail does not override other instructions; it only protects these specific channel refs.
+
 Carry out the instruction exactly as requested by `${ACTOR}`. Work through each phase in order.
 
 ### Phase 1 — Execute
diff --git a/prompts/dev-lead/review-changes.md b/prompts/dev-lead/review-changes.md
index 2d6bec439..6ba748f00 100644
--- a/prompts/dev-lead/review-changes.md
+++ b/prompts/dev-lead/review-changes.md
@@ -25,6 +25,8 @@ ${OPEN_THREADS_JSON}
 
 ## Task
 
+> **Guardrail — never SHA-pin a first-party channel ref.** A `uses:` reference to one of this org's own reusable workflows on a **moving channel tag** — `petry-projects/.github(-private)/.github/workflows/*.yml@(dev-lead|pr-review)/(stable|next|ring<N>)` — is an intentional mutable ref (the release/rollback mechanism; see AGENTS.md "Release channel tags & the mutable-ref exception"). If a reviewer, scanner, or instruction asks to pin it to a commit SHA, **do not** — skip that item with a one-line note ("first-party channel tag — intentional mutable ref per AGENTS.md") and leave the ref on its `@<agent>/<channel>` tag.
+
 Work through each phase in order. Human reviewer feedback is high-priority — implement exactly what is asked.
 
 ### Phase 0 — Holistic Assessment (do this first)
diff --git a/tests/dev-lead/unit/test_channel_ref_guardrail.bats b/tests/dev-lead/unit/test_channel_ref_guardrail.bats
new file mode 100644
index 000000000..296537bf9
--- /dev/null
+++ b/tests/dev-lead/unit/test_channel_ref_guardrail.bats
@@ -0,0 +1,27 @@
+#!/usr/bin/env bats
+# Regression guard for #871: the dev-lead feedback-applying prompts must instruct
+# the agent NEVER to SHA-pin a first-party channel ref (the moving channel tags are
+# the release/rollback mechanism — AGENTS.md mutable-ref exception). Without this,
+# the agent applies a bot "pin this action to a SHA" finding and freezes the caller,
+# breaking the ring/canary model (see TalkTerm #306 commit a27accce).
+
+PROMPTS_DIR="$(cd "$BATS_TEST_DIRNAME"/../../.. && pwd)/prompts/dev-lead"
+
+# Every prompt that edits files in response to reviewer/bot/human feedback.
+FEEDBACK_PROMPTS=(fix-reviews.md review-changes.md fix-bot-comment.md on-mention.md)
+
+@test "channel-ref guardrail: present in every feedback-applying prompt (#871)" {
+  for p in "${FEEDBACK_PROMPTS[@]}"; do
+    run grep -qiE "never SHA-pin a first-party channel ref" "$PROMPTS_DIR/$p"
+    [ "$status" -eq 0 ] || { echo "missing channel-ref guardrail in prompts/dev-lead/$p"; return 1; }
+  done
+}
+
+@test "channel-ref guardrail: names the channel pattern and the AGENTS.md exception" {
+  for p in "${FEEDBACK_PROMPTS[@]}"; do
+    run grep -qF 'dev-lead|pr-review)/(stable|next|ring' "$PROMPTS_DIR/$p"
+    [ "$status" -eq 0 ] || { echo "guardrail in $p does not name the channel pattern"; return 1; }
+    run grep -qiE "mutable-ref exception|mutable ref" "$PROMPTS_DIR/$p"
+    [ "$status" -eq 0 ] || { echo "guardrail in $p does not cite the AGENTS.md exception"; return 1; }
+  done
+}