diff --git a/dev/dev-agent.sh b/dev/dev-agent.sh
index 21eba37..be85d88 100755
--- a/dev/dev-agent.sh
+++ b/dev/dev-agent.sh
@@ -1239,6 +1239,8 @@ Instructions:
         # Do NOT update LAST_PHASE_MTIME here — leave it stale so the outer
         # loop detects the change on its next tick and dispatches the new phase.
         REVIEW_FOUND=true  # Prevent timeout injection
+        # Clean up review-poll sentinel if it exists (session already advanced)
+        rm -f "/tmp/review-injected-${PROJECT_NAME}-${PR_NUMBER}"
         break
       fi
 
@@ -1273,6 +1275,15 @@ Instructions:
           [ -n "$VERDICT" ] && log "verdict from formal review: $VERDICT"
         fi
 
+        # Skip injection if review-poll.sh already injected (sentinel present)
+        REVIEW_SENTINEL="/tmp/review-injected-${PROJECT_NAME}-${PR_NUMBER}"
+        if [ -n "$VERDICT" ] && [ -f "$REVIEW_SENTINEL" ]; then
+          log "review already injected by review-poll (sentinel exists) — skipping"
+          rm -f "$REVIEW_SENTINEL"
+          REVIEW_FOUND=true
+          break
+        fi
+
         if [ "$VERDICT" = "APPROVE" ]; then
           REVIEW_FOUND=true
           inject_into_session "Approved! PR #${PR_NUMBER} has been approved by the reviewer.
diff --git a/review/review-poll.sh b/review/review-poll.sh
index 799cc14..4fd1f0f 100755
--- a/review/review-poll.sh
+++ b/review/review-poll.sh
@@ -156,6 +156,8 @@ Instructions:
   tmux delete-buffer -b "review-inject-${pr_num}" 2>/dev/null || true
   rm -f "${inject_tmp}"
   log "  #${pr_num} review (${verdict}) injected into session ${session}"
+  # Write sentinel so dev-agent.sh awaiting_review loop skips its own injection
+  touch "/tmp/review-injected-${PROJECT_NAME}-${pr_num}"
 }
 
 while IFS= read -r line; do