diff --git a/apps/journal/package.json b/apps/journal/package.json
index 62c0ca7..b036f5b 100644
--- a/apps/journal/package.json
+++ b/apps/journal/package.json
@@ -36,7 +36,7 @@
     "react": "catalog:",
     "react-dom": "catalog:",
     "react-router": "catalog:",
-    "zod": "^3.25.0"
+    "zod": "^4.0.0"
   },
   "devDependencies": {
     "@react-router/dev": "catalog:",
diff --git a/apps/mobile/package.json b/apps/mobile/package.json
index a3b13dc..4bd2597 100644
--- a/apps/mobile/package.json
+++ b/apps/mobile/package.json
@@ -66,7 +66,7 @@
     "react-native-safe-area-context": "~5.6.2",
     "react-native-screens": "~4.23.0",
     "use-latest-callback": "^0.3.3",
-    "zod": "^3.25.76"
+    "zod": "^4.0.0"
   },
   "devDependencies": {
     "@testing-library/react-native": "^13.3.3",
diff --git a/packages/api/package.json b/packages/api/package.json
index 2e8b628..1c5432e 100644
--- a/packages/api/package.json
+++ b/packages/api/package.json
@@ -10,6 +10,6 @@
     "typecheck": "tsc"
   },
   "dependencies": {
-    "zod": "^3.25.0"
+    "zod": "^4.0.0"
   }
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index c61e98a..3cd855d 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -267,8 +267,8 @@ importers:
         specifier: 'catalog:'
         version: 7.14.1(react-dom@19.2.5(react@19.2.5))(react@19.2.5)
       zod:
-        specifier: ^3.25.0
-        version: 3.25.76
+        specifier: ^4.0.0
+        version: 4.3.6
     devDependencies:
       '@react-router/dev':
         specifier: 'catalog:'
@@ -418,8 +418,8 @@ importers:
         specifier: ^0.3.3
         version: 0.3.3(react@19.2.5)
       zod:
-        specifier: ^3.25.76
-        version: 3.25.76
+        specifier: ^4.0.0
+        version: 4.3.6
     devDependencies:
       '@testing-library/react-native':
         specifier: ^13.3.3
@@ -576,8 +576,8 @@ importers:
   packages/api:
     dependencies:
       zod:
-        specifier: ^3.25.0
-        version: 3.25.76
+        specifier: ^4.0.0
+        version: 4.3.6
 
   packages/db:
     dependencies:
@@ -7671,6 +7671,9 @@ packages:
   zod@3.25.76:
     resolution: {integrity: sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==}
 
+  zod@4.3.6:
+    resolution: {integrity: sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==}
+
 snapshots:
 
   '@adobe/css-tools@4.4.4': {}
@@ -15661,3 +15664,5 @@ snapshots:
   yocto-queue@0.1.0: {}
 
   zod@3.25.76: {}
+
+  zod@4.3.6: {}