diff --git a/src/triggers/github/pr-conflict-detected.ts b/src/triggers/github/pr-conflict-detected.ts
index 75e289c5..64a593c8 100644
--- a/src/triggers/github/pr-conflict-detected.ts
+++ b/src/triggers/github/pr-conflict-detected.ts
@@ -35,8 +35,27 @@ export class PRConflictDetectedTrigger implements TriggerHandler {
 
 		const payload = ctx.payload;
 
-		// Only trigger on synchronize events (when PR head is pushed/updated)
-		if (payload.action !== 'synchronize') return false;
+		// Trigger on `opened`, `reopened`, and `synchronize` — the three
+		// actions that produce a candidate head SHA whose mergeability we
+		// should check:
+		//   - opened: brand-new PR. Bit us on ucho/PR #226 (2026-05-02) —
+		//     the impl bot opened the PR already CONFLICTING against `dev`,
+		//     and because the matcher previously accepted only `synchronize`,
+		//     `resolve-conflicts` never fired until someone pushed a commit.
+		//   - reopened: closed PR brought back; mergeability may have flipped
+		//     against the now-advanced base.
+		//   - synchronize: new commit pushed to existing PR (the original
+		//     intent of this trigger).
+		// `closed`, `edited`, `labeled`, etc. correctly stay rejected.
+		// The handler's `mergeable === null` retry loop covers GitHub's async
+		// mergeability computation that's most prominent on `opened`.
+		if (
+			payload.action !== 'opened' &&
+			payload.action !== 'reopened' &&
+			payload.action !== 'synchronize'
+		) {
+			return false;
+		}
 
 		return true;
 	}
diff --git a/tests/unit/triggers/pr-conflict-detected.test.ts b/tests/unit/triggers/pr-conflict-detected.test.ts
index f186223b..55fc10be 100644
--- a/tests/unit/triggers/pr-conflict-detected.test.ts
+++ b/tests/unit/triggers/pr-conflict-detected.test.ts
@@ -77,21 +77,43 @@ describe('PRConflictDetectedTrigger', () => {
 			expect(trigger.matches(ctx)).toBe(false);
 		});
 
-		it('does not match non-synchronize action', () => {
+		// PR #226 (2026-05-02) regression pin: the impl bot opened the PR
+		// already conflicting against `dev`, but the matcher previously
+		// accepted only `synchronize`, so resolve-conflicts never fired
+		// until someone pushed a commit. Both `opened` and `reopened` must
+		// match so the handler's mergeability retry + dispatch path runs.
+		it('matches opened action (PR #226 regression pin)', () => {
 			const ctx: TriggerContext = {
 				project: mockProject,
 				source: 'github',
 				payload: makeSynchronizePayload({ action: 'opened' }),
 			};
 
-			expect(trigger.matches(ctx)).toBe(false);
+			expect(trigger.matches(ctx)).toBe(true);
+		});
+
+		it('matches reopened action', () => {
+			const ctx: TriggerContext = {
+				project: mockProject,
+				source: 'github',
+				payload: makeSynchronizePayload({ action: 'reopened' }),
+			};
+
+			expect(trigger.matches(ctx)).toBe(true);
 		});
 
-		it('does not match closed action', () => {
+		it.each([
+			['closed'],
+			['edited'],
+			['labeled'],
+			['unlabeled'],
+			['assigned'],
+			['ready_for_review'],
+		])('does not match %s action', (action) => {
 			const ctx: TriggerContext = {
 				project: mockProject,
 				source: 'github',
-				payload: makeSynchronizePayload({ action: 'closed' }),
+				payload: makeSynchronizePayload({ action }),
 			};
 
 			expect(trigger.matches(ctx)).toBe(false);