diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46de017..d913833 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,27 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.4.0] - 2026-04-28
+
+### Added
+
+- Unified memory quality gate in `src/memory-quality.ts` as the single source of truth for all memory quality rules.
+- CRITICAL MEMORY RULES in compaction prompt with explicit good/bad examples.
+- Auto-supersede migration `2026-04-28-quality-cleanup` that marks low-quality compaction memories as superseded on first load.
+
+### Changed
+
+- Memory quality rules now apply to all memory types, not just project entries.
+- Compaction prompt explicitly instructs model that most compactions should produce zero memories.
+- Low-quality compaction memories (progress snapshots, implementation notes, session-internal notes) are automatically superseded during workspace memory normalization.
+
+### Migration Notes
+
+- Existing low-quality `source: "compaction"` entries will be marked as `superseded` once on first load after upgrade.
+- Explicit and manual memories are never affected by quality cleanup.
+- Superseded entries are retained on disk with `quality_cleanup` tags for audit purposes.
+- Migration is idempotent and runs exactly once per workspace.
+
 ## [1.3.3] - 2026-04-28
 
 ### Fixed
diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 3d5c045..de0435a 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,5 +1,55 @@
 # Release Notes
 
+## 1.4.0 (2026-04-28)
+
+### Memory Quality Cleanup
+
+This minor release automatically improves memory quality for all existing users on upgrade. Low-quality compaction memories are identified and superseded without requiring manual cleanup.
+
+### What Changed
+
+- **Unified quality gate**: All memory types (feedback, decision, project, reference) now share the same quality rules instead of only project entries having a quality check.
+- **Hardened compaction prompt**: The model is explicitly instructed that most compactions should produce zero memories, with clear good/bad examples.
+- **Auto-supersede migration**: On first load after upgrade, existing low-quality `compaction` memories are automatically marked as `superseded` with quality tags. Explicit and manual memories are never affected.
+
+### What Gets Cleaned Up
+
+Low-quality memory patterns that are now rejected/superseded:
+
+- Progress snapshots: "Wave 1 completed successfully", "180 tests passed"
+- Session-internal notes: "The assistant reviewed feedback and updated the plan"
+- Implementation notes: "Implemented X in plugin.ts"
+- Commit/CI references: "Commit a762e86 contains the fix"
+- Raw errors and stack traces
+- Temporary status: "Currently running npm test"
+
+### Migration Behavior
+
+- Runs exactly once per workspace (idempotent, non-destructive)
+- Only affects `source: "compaction"` entries
+- Explicit/manual memories are protected
+- Superseded entries retain `status: "superseded"` and quality tags for audit
+- No user action required
+
+### Upgrade Notes
+
+- No configuration changes required.
+- Existing workspace memory files are automatically cleaned on first load.
+- The OpenCode config entry stays the same:
+
+```json
+{
+  "plugin": ["opencode-working-memory"]
+}
+```
+
+### Validation
+
+- `npm test` (196 tests)
+- `npm run typecheck`
+
+---
+
 ## 1.3.2 (2026-04-27)
 
 ### CI Compatibility Patch
diff --git a/package.json b/package.json
index 6d44fd6..8f05d3b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "opencode-working-memory",
-  "version": "1.3.3",
+  "version": "1.4.0",
   "description": "Three-layer memory architecture for OpenCode with workspace memory and hot session state",
   "type": "module",
   "main": "index.ts",