diff --git a/apps/zbugs/package.json b/apps/zbugs/package.json
index d0fc3c1bd7..3934e90a7b 100644
--- a/apps/zbugs/package.json
+++ b/apps/zbugs/package.json
@@ -57,7 +57,7 @@
     "prettier": "^3.0.3",
     "tailwindcss": "^3.0.23",
     "tsx": "^4.19.1",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "universal-user-agent": "^7.0.2",
     "vite": "^5.2.0",
     "vite-plugin-svgr": "^4.2.0",
diff --git a/package-lock.json b/package-lock.json
index 3364ec28fb..c83bbcffc5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -67,7 +67,7 @@
         "prettier": "^3.0.3",
         "tailwindcss": "^3.0.23",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "universal-user-agent": "^7.0.2",
         "vite": "^5.2.0",
         "vite-plugin-svgr": "^4.2.0",
@@ -16201,9 +16201,10 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.5.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.4.tgz",
-      "integrity": "sha512-Mtq29sKDAEYP7aljRgtPOpTvOfbwRWlS6dPRzwjdE+C0R4brX/GUyhHSecbHMFLNBLcJIPt9nl9yG5TZ1weH+Q==",
+      "version": "5.6.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.6.3.tgz",
+      "integrity": "sha512-hjcS1mhfuyi4WW8IWtjP7brDrG2cuDZukyrYrSauoXGNgx0S7zceP07adYkJycEr56BOUTNPzbInooiN3fn1qw==",
+      "license": "Apache-2.0",
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
@@ -17342,7 +17343,7 @@
         "functional-red-black-tree": "^1.0.1",
         "mersenne-twister": "^1.1.0",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3"
+        "typescript": "^5.6.3"
       }
     },
     "packages/cf-shared": {
@@ -17369,7 +17370,7 @@
         "@rocicorp/logger": "^5.3.0",
         "@rocicorp/prettier-config": "^0.2.0",
         "replicache": "15.2.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3"
       }
     },
@@ -17406,7 +17407,7 @@
         "shared": "0.0.0",
         "sinon": "^13.0.1",
         "tsc-alias": "^1.8.10",
-        "typescript": "^5.5.3"
+        "typescript": "^5.6.3"
       }
     },
     "packages/replicache-perf": {
@@ -17427,7 +17428,7 @@
         "replicache": "15.2.1",
         "shared": "0.0.0",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "xbytes": "^1.7.0"
       }
     },
@@ -17523,7 +17524,7 @@
         "@vitest/browser": "^2.0.3",
         "fast-check": "^3.18.0",
         "pkg-up": "^5.0.0",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3"
       }
     },
@@ -17589,7 +17590,7 @@
         "esbuild": "^0.20.2",
         "replicache": "15.2.1",
         "tsc-alias": "^1.8.10",
-        "typescript": "^5.5.3"
+        "typescript": "^5.6.3"
       },
       "engines": {
         "node": ">=20"
@@ -17636,7 +17637,7 @@
         "concurrently": "^8.2.1",
         "shared": "0.0.0",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3"
       }
     },
@@ -17705,7 +17706,7 @@
         "shared": "0.0.0",
         "sinon": "^13.0.1",
         "tsc-alias": "^1.8.10",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "zero-protocol": "0.0.0"
       }
     },
@@ -17762,7 +17763,7 @@
         "@vitest/browser": "^2.0.3",
         "fast-check": "^3.18.0",
         "pkg-up": "^5.0.0",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3"
       }
     },
@@ -17797,7 +17798,7 @@
         "@rocicorp/eslint-config": "^0.5.1",
         "@rocicorp/prettier-config": "^0.2.0",
         "shared": "0.0.0",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "zql": "0.0.0"
       }
     },
@@ -17898,7 +17899,7 @@
         "playwright": "^1.43.1",
         "replicache": "15.2.1",
         "shared": "0.0.0",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "wa-sqlite": "github:rhashimoto/wa-sqlite#ca2084cdd188c56532ba3e272696d0b9e21a23bf",
         "zod": "^3.21.4"
       }
@@ -17961,7 +17962,7 @@
         "nanoid": "^4.0.2",
         "playwright": "^1.43.1",
         "shared": "0.0.0",
-        "typescript": "^5.5.3"
+        "typescript": "^5.6.3"
       }
     },
     "packages/zqlite-zero-cache-shared": {
@@ -19459,7 +19460,7 @@
         "replicache": "15.2.1",
         "semver": "^7.5.4",
         "tsc-alias": "^1.8.10",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "ws": "^8.18.0",
         "xxhash-wasm": "^1.0.2"
       },
@@ -21939,7 +21940,7 @@
         "functional-red-black-tree": "^1.0.1",
         "mersenne-twister": "^1.1.0",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3"
+        "typescript": "^5.6.3"
       }
     },
     "buffer": {
@@ -22615,7 +22616,7 @@
         "@rocicorp/logger": "^5.3.0",
         "@rocicorp/prettier-config": "^0.2.0",
         "replicache": "15.2.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3"
       }
     },
@@ -27435,7 +27436,7 @@
         "shared": "0.0.0",
         "sinon": "^13.0.1",
         "tsc-alias": "^1.8.10",
-        "typescript": "^5.5.3"
+        "typescript": "^5.6.3"
       },
       "dependencies": {
         "esbuild": {
@@ -27490,7 +27491,7 @@
         "replicache": "15.2.1",
         "shared": "0.0.0",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "xbytes": "^1.7.0"
       },
       "dependencies": {
@@ -27764,7 +27765,7 @@
         "fast-check": "^3.18.0",
         "pkg-up": "^5.0.0",
         "semver": "^7.5.4",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3",
         "xxhash-wasm": "^1.0.2"
       },
@@ -29237,9 +29238,9 @@
       }
     },
     "typescript": {
-      "version": "5.5.4",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.5.4.tgz",
-      "integrity": "sha512-Mtq29sKDAEYP7aljRgtPOpTvOfbwRWlS6dPRzwjdE+C0R4brX/GUyhHSecbHMFLNBLcJIPt9nl9yG5TZ1weH+Q=="
+      "version": "5.6.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.6.3.tgz",
+      "integrity": "sha512-hjcS1mhfuyi4WW8IWtjP7brDrG2cuDZukyrYrSauoXGNgx0S7zceP07adYkJycEr56BOUTNPzbInooiN3fn1qw=="
     },
     "typical": {
       "version": "4.0.0",
@@ -29973,7 +29974,7 @@
         "rehype-sanitize": "^6.0.0",
         "tailwindcss": "^3.0.23",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "universal-user-agent": "^7.0.2",
         "vite": "^5.2.0",
         "vite-plugin-svgr": "^4.2.0",
@@ -30131,7 +30132,7 @@
         "postgres-array": "^3.0.2",
         "shared": "0.0.0",
         "tsx": "^4.19.1",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3",
         "ws": "^8.18.0",
         "xxhash-wasm": "^1.0.2",
@@ -30186,7 +30187,7 @@
         "shared": "0.0.0",
         "sinon": "^13.0.1",
         "tsc-alias": "^1.8.10",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "zero-protocol": "0.0.0"
       },
       "dependencies": {
@@ -30236,7 +30237,7 @@
         "fast-check": "^3.18.0",
         "pkg-up": "^5.0.0",
         "semver": "^7.5.4",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "vitest": "^2.0.3"
       },
       "dependencies": {
@@ -30258,7 +30259,7 @@
         "@rocicorp/eslint-config": "^0.5.1",
         "@rocicorp/prettier-config": "^0.2.0",
         "shared": "0.0.0",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "zql": "0.0.0"
       }
     },
@@ -30302,7 +30303,7 @@
         "playwright": "^1.43.1",
         "replicache": "15.2.1",
         "shared": "0.0.0",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "wa-sqlite": "github:rhashimoto/wa-sqlite#ca2084cdd188c56532ba3e272696d0b9e21a23bf",
         "zod": "^3.21.4"
       },
@@ -30338,7 +30339,7 @@
         "pg-logical-replication": "^2.0.7",
         "playwright": "^1.43.1",
         "shared": "0.0.0",
-        "typescript": "^5.5.3",
+        "typescript": "^5.6.3",
         "zql": "0.0.0"
       },
       "dependencies": {
diff --git a/packages/btree/package.json b/packages/btree/package.json
index dcbf630ee1..6c10752572 100644
--- a/packages/btree/package.json
+++ b/packages/btree/package.json
@@ -53,6 +53,6 @@
     "functional-red-black-tree": "^1.0.1",
     "mersenne-twister": "^1.1.0",
     "tsx": "^4.19.1",
-    "typescript": "^5.5.3"
+    "typescript": "^5.6.3"
   }
 }
diff --git a/packages/datadog/package.json b/packages/datadog/package.json
index a4f824350f..b00310022a 100644
--- a/packages/datadog/package.json
+++ b/packages/datadog/package.json
@@ -9,7 +9,7 @@
     "@rocicorp/logger": "^5.3.0",
     "@rocicorp/prettier-config": "^0.2.0",
     "replicache": "15.2.1",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "vitest": "^2.0.3"
   },
   "scripts": {
diff --git a/packages/replicache-perf/package.json b/packages/replicache-perf/package.json
index 076edd469b..fb058c9780 100644
--- a/packages/replicache-perf/package.json
+++ b/packages/replicache-perf/package.json
@@ -27,7 +27,7 @@
     "replicache": "15.2.1",
     "shared": "0.0.0",
     "tsx": "^4.19.1",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "xbytes": "^1.7.0"
   },
   "eslintConfig": {
diff --git a/packages/replicache/package.json b/packages/replicache/package.json
index 1386f86671..0115de6b1a 100644
--- a/packages/replicache/package.json
+++ b/packages/replicache/package.json
@@ -45,7 +45,7 @@
     "shared": "0.0.0",
     "sinon": "^13.0.1",
     "tsc-alias": "^1.8.10",
-    "typescript": "^5.5.3"
+    "typescript": "^5.6.3"
   },
   "type": "module",
   "main": "out/replicache.js",
diff --git a/packages/shared/package.json b/packages/shared/package.json
index 5e578d1eac..f7ba933a9b 100644
--- a/packages/shared/package.json
+++ b/packages/shared/package.json
@@ -27,7 +27,7 @@
     "@vitest/browser": "^2.0.3",
     "fast-check": "^3.18.0",
     "pkg-up": "^5.0.0",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "vitest": "^2.0.3"
   },
   "eslintConfig": {
diff --git a/packages/zero-cache/package.json b/packages/zero-cache/package.json
index f1d886850f..29a4b14198 100644
--- a/packages/zero-cache/package.json
+++ b/packages/zero-cache/package.json
@@ -56,7 +56,7 @@
     "concurrently": "^8.2.1",
     "shared": "0.0.0",
     "tsx": "^4.19.1",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "vitest": "^2.0.3"
   },
   "eslintConfig": {
diff --git a/packages/zero-client/package.json b/packages/zero-client/package.json
index 7b6a96dfde..42f8ab4e0d 100644
--- a/packages/zero-client/package.json
+++ b/packages/zero-client/package.json
@@ -28,7 +28,7 @@
     "shared": "0.0.0",
     "sinon": "^13.0.1",
     "tsc-alias": "^1.8.10",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "zero-protocol": "0.0.0"
   },
   "eslintConfig": {
diff --git a/packages/zero-integration-test/package.json b/packages/zero-integration-test/package.json
index 7414c6fdfc..77fd776689 100644
--- a/packages/zero-integration-test/package.json
+++ b/packages/zero-integration-test/package.json
@@ -28,7 +28,7 @@
     "@vitest/browser": "^2.0.3",
     "fast-check": "^3.18.0",
     "pkg-up": "^5.0.0",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "vitest": "^2.0.3"
   },
   "eslintConfig": {
diff --git a/packages/zero-protocol/package.json b/packages/zero-protocol/package.json
index fc8b84480e..9bb7bdf5fd 100644
--- a/packages/zero-protocol/package.json
+++ b/packages/zero-protocol/package.json
@@ -18,7 +18,7 @@
     "@rocicorp/prettier-config": "^0.2.0",
     "zql": "0.0.0",
     "shared": "0.0.0",
-    "typescript": "^5.5.3"
+    "typescript": "^5.6.3"
   },
   "exports": {
     ".": "./src/mod.ts",
diff --git a/packages/zero/package.json b/packages/zero/package.json
index e5c3039d37..ee17bde8e0 100644
--- a/packages/zero/package.json
+++ b/packages/zero/package.json
@@ -46,7 +46,7 @@
     "esbuild": "^0.20.2",
     "replicache": "15.2.1",
     "tsc-alias": "^1.8.10",
-    "typescript": "^5.5.3"
+    "typescript": "^5.6.3"
   },
   "type": "module",
   "main": "out/zero.js",
diff --git a/packages/zql/package.json b/packages/zql/package.json
index 5b9a86b1b7..a650d4acdb 100644
--- a/packages/zql/package.json
+++ b/packages/zql/package.json
@@ -24,7 +24,7 @@
     "playwright": "^1.43.1",
     "replicache": "15.2.1",
     "shared": "0.0.0",
-    "typescript": "^5.5.3",
+    "typescript": "^5.6.3",
     "wa-sqlite": "github:rhashimoto/wa-sqlite#ca2084cdd188c56532ba3e272696d0b9e21a23bf",
     "zod": "^3.21.4"
   },
diff --git a/packages/zql/src/zql/ivm/lookahead-iterator.test.ts b/packages/zql/src/zql/ivm/lookahead-iterator.test.ts
index 2fc4dbec86..99e14f6a02 100644
--- a/packages/zql/src/zql/ivm/lookahead-iterator.test.ts
+++ b/packages/zql/src/zql/ivm/lookahead-iterator.test.ts
@@ -94,7 +94,7 @@ test('basics', () => {
 });
 
 class ExpensiveIterator {
-  #iter = [1, 2, 3][Symbol.iterator]();
+  #iter = [1, 2, 3].values();
 
   returned: unknown[] = [];
   thrown: unknown[] = [];
@@ -103,7 +103,7 @@ class ExpensiveIterator {
     return this.#iter.next();
   }
 
-  return(value?: unknown) {
+  return(value?: undefined) {
     this.returned.push(value);
     this.#iter.return?.(value);
     return {done: true, value: undefined};
diff --git a/packages/zqlite/package.json b/packages/zqlite/package.json
index e1eae3514b..a24eda96fb 100644
--- a/packages/zqlite/package.json
+++ b/packages/zqlite/package.json
@@ -26,7 +26,7 @@
     "nanoid": "^4.0.2",
     "playwright": "^1.43.1",
     "shared": "0.0.0",
-    "typescript": "^5.5.3"
+    "typescript": "^5.6.3"
   },
   "eslintConfig": {
     "extends": "../../eslint-config.json"