diff --git a/packages/omgidl-serialization/package.json b/packages/omgidl-serialization/package.json
index 941b543..1f7f8ce 100644
--- a/packages/omgidl-serialization/package.json
+++ b/packages/omgidl-serialization/package.json
@@ -48,7 +48,7 @@
     "typescript": "4.9.5"
   },
   "dependencies": {
-    "@foxglove/cdr": "2.1.0",
+    "@foxglove/cdr": "3.0.0",
     "@foxglove/message-definition": "^0.2.0"
   }
 }
diff --git a/packages/omgidl-serialization/src/MessageReader.ts b/packages/omgidl-serialization/src/MessageReader.ts
index 4c04e17..7a4e993 100644
--- a/packages/omgidl-serialization/src/MessageReader.ts
+++ b/packages/omgidl-serialization/src/MessageReader.ts
@@ -6,8 +6,13 @@ import {
 
 export type Deserializer = (
   reader: CdrReader,
+  /**
+   * Optional length only applied for string types as character length.
+   * Prevents reader from reading sequence length again if already read via header.
+   */
   length?: number,
 ) => boolean | number | bigint | string;
+
 export type ArrayDeserializer = (
   reader: CdrReader,
   count: number,
@@ -93,7 +98,7 @@ export class MessageReader<T = unknown> {
       let fieldLength = field.arrayLength;
       if (readMemberHeader) {
         const { id, objectSize: objectSizeBytes } = reader.emHeader();
-        const itemSize = typeToByteLength[field.type];
+        const itemSize = typeToByteLength(field.type);
         if (itemSize != undefined) {
           fieldLength ??= Math.ceil(objectSizeBytes / itemSize);
         }
@@ -147,20 +152,28 @@ export class MessageReader<T = unknown> {
   }
 }
 
-const typeToByteLength: Record<string, number> = {
-  bool: 1,
-  int8: 1,
-  uint8: 1,
-  int16: 2,
-  uint16: 2,
-  int32: 4,
-  uint32: 4,
-  int64: 8,
-  uint64: 8,
-  float32: 4,
-  float64: 8,
-  string: 1,
-};
+function typeToByteLength(type: string): number | undefined {
+  switch (type) {
+    case "bool":
+    case "int8":
+    case "uint8":
+    case "string":
+      return 1;
+    case "int16":
+    case "uint16":
+      return 2;
+    case "int32":
+    case "uint32":
+    case "float32":
+      return 4;
+    case "int64":
+    case "uint64":
+    case "float64":
+      return 8;
+    default:
+      return undefined;
+  }
+}
 
 const deserializers = new Map<string, Deserializer>([
   ["bool", (reader) => Boolean(reader.int8())],
diff --git a/yarn.lock b/yarn.lock
index b78c056..82974a7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -452,10 +452,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@foxglove/cdr@npm:2.1.0":
-  version: 2.1.0
-  resolution: "@foxglove/cdr@npm:2.1.0"
-  checksum: 153632a8911a76d047d896f0a17e12b5a6779465a35790c2fe349efc0eb8a618c877d015a066d8b13a804f0c72131a7e9ca0bf48ed116aa3095a3d7252ab1062
+"@foxglove/cdr@npm:3.0.0":
+  version: 3.0.0
+  resolution: "@foxglove/cdr@npm:3.0.0"
+  checksum: 3ad9b7f92b842aaf8e6f968d0deb060e8cd5b63ee536fce34563bca66d4cb8f488cb03d3b77481a68bbbcbd5fb11e49181575585644046f38401a678218fd589
   languageName: node
   linkType: hard
 
@@ -534,7 +534,7 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@foxglove/omgidl-serialization@workspace:packages/omgidl-serialization"
   dependencies:
-    "@foxglove/cdr": 2.1.0
+    "@foxglove/cdr": 3.0.0
     "@foxglove/message-definition": ^0.2.0
     "@foxglove/omgidl-parser": "workspace:*"
     "@sounisi5011/jest-binary-data-matchers": 1.2.1