diff --git a/src/core/Ros.ts b/src/core/Ros.ts
index e64c7f70c..4a43437fe 100644
--- a/src/core/Ros.ts
+++ b/src/core/Ros.ts
@@ -646,6 +646,11 @@ export default class Ros extends EventEmitter<
         const arrayLen = theType.fieldarraylen[i];
         const fieldName = theType.fieldnames[i];
         const fieldType = theType.fieldtypes[i];
+        if (fieldName === undefined || fieldType === undefined) {
+          throw new Error(
+            "Received mismatched type definition vector lengths!",
+          );
+        }
         if (!fieldType.includes("/")) {
           // check the fieldType includes '/' or not
           if (arrayLen === -1) {
@@ -677,7 +682,11 @@ export default class Ros extends EventEmitter<
       return typeDefDict;
     };
 
-    return decodeTypeDefsRec(defs[0], defs);
+    if (defs[0]) {
+      return decodeTypeDefsRec(defs[0], defs);
+    } else {
+      return {};
+    }
   }
 
   /**
diff --git a/src/urdf/UrdfBox.ts b/src/urdf/UrdfBox.ts
index 4561d7a1b..184a8cb33 100644
--- a/src/urdf/UrdfBox.ts
+++ b/src/urdf/UrdfBox.ts
@@ -22,7 +22,7 @@ export default class UrdfBox {
     const size: Optional<string[]> = xml
       .getAttribute(UrdfAttrs.Size)
       ?.split(" ");
-    if (size?.length !== 3) {
+    if (!(size?.[0] && size[1] && size[2])) {
       return;
     }
 
diff --git a/src/urdf/UrdfColor.ts b/src/urdf/UrdfColor.ts
index 0cc42b569..cc1127aa5 100644
--- a/src/urdf/UrdfColor.ts
+++ b/src/urdf/UrdfColor.ts
@@ -33,7 +33,7 @@ export default class UrdfColor {
     const rgba: Optional<string[]> = xml
       .getAttribute(UrdfAttrs.Rgba)
       ?.split(" ");
-    if (rgba?.length !== 4) {
+    if (!(rgba?.[0] && rgba[1] && rgba[2] && rgba[3])) {
       return;
     }
 
diff --git a/src/urdf/UrdfJoint.ts b/src/urdf/UrdfJoint.ts
index 43a6ac3ae..7e0026ff7 100644
--- a/src/urdf/UrdfJoint.ts
+++ b/src/urdf/UrdfJoint.ts
@@ -31,17 +31,17 @@ export default class UrdfJoint {
     this.type = xml.getAttribute(UrdfAttrs.Type);
 
     const parents = xml.getElementsByTagName(UrdfAttrs.Parent);
-    if (parents.length > 0) {
+    if (parents[0]) {
       this.parent = parents[0].getAttribute(UrdfAttrs.Link);
     }
 
     const children = xml.getElementsByTagName(UrdfAttrs.Child);
-    if (children.length > 0) {
+    if (children[0]) {
       this.child = children[0].getAttribute(UrdfAttrs.Link);
     }
 
     const limits = xml.getElementsByTagName(UrdfAttrs.Limit);
-    if (limits.length > 0) {
+    if (limits[0]) {
       this.minval = parseFloat(
         limits[0].getAttribute(UrdfAttrs.Lower) ?? "NaN",
       );
@@ -52,12 +52,12 @@ export default class UrdfJoint {
 
     // Origin
     const origins = xml.getElementsByTagName(UrdfAttrs.Origin);
-    if (origins.length > 0) {
+    if (origins[0]) {
       this.origin = parseUrdfOrigin(origins[0]);
     }
 
     const axis = xml.getElementsByTagName(UrdfAttrs.Axis);
-    if (axis.length > 0) {
+    if (axis[0]) {
       const xyzValue = axis[0].getAttribute(UrdfAttrs.Xyz)?.split(" ");
       if (!xyzValue || xyzValue.length !== 3) {
         throw new Error(
diff --git a/src/urdf/UrdfMaterial.ts b/src/urdf/UrdfMaterial.ts
index 210e81c5b..385f360aa 100644
--- a/src/urdf/UrdfMaterial.ts
+++ b/src/urdf/UrdfMaterial.ts
@@ -21,13 +21,13 @@ export default class UrdfMaterial {
 
     // Texture
     const textures = xml.getElementsByTagName(UrdfAttrs.Texture);
-    if (textures.length > 0) {
+    if (textures[0]) {
       this.textureFilename = textures[0].getAttribute(UrdfAttrs.Filename);
     }
 
     // Color
     const colors = xml.getElementsByTagName(UrdfAttrs.Color);
-    if (colors.length > 0) {
+    if (colors[0]) {
       // Parse the RBGA string
       this.color = new UrdfColor({
         xml: colors[0],
diff --git a/src/urdf/UrdfMesh.ts b/src/urdf/UrdfMesh.ts
index f15d75a68..c876d1bcc 100644
--- a/src/urdf/UrdfMesh.ts
+++ b/src/urdf/UrdfMesh.ts
@@ -24,7 +24,7 @@ export default class UrdfMesh {
     const scale: Optional<string[]> = xml
       .getAttribute(UrdfAttrs.Scale)
       ?.split(" ");
-    if (scale?.length !== 3) {
+    if (!(scale?.[0] && scale[1] && scale[2])) {
       return;
     }
 
diff --git a/src/urdf/UrdfModel.ts b/src/urdf/UrdfModel.ts
index 084ca82a1..0a8e5cd4e 100644
--- a/src/urdf/UrdfModel.ts
+++ b/src/urdf/UrdfModel.ts
@@ -72,8 +72,9 @@ export default class UrdfModel {
             break;
           }
 
-          if (this.materials[material.name].isLink()) {
-            this.materials[material.name].assign(material);
+          const existingMaterial = this.materials[material.name];
+          if (existingMaterial?.isLink()) {
+            existingMaterial.assign(material);
           } else {
             console.warn(`Material ${material.name} is not unique.`);
           }
@@ -95,8 +96,9 @@ export default class UrdfModel {
               continue;
             }
 
-            if (Object.hasOwn(this.materials, mat.name)) {
-              item.material = this.materials[mat.name];
+            const material = this.materials[mat.name];
+            if (material) {
+              item.material = material;
             } else {
               this.materials[mat.name] = mat;
             }
diff --git a/src/urdf/UrdfUtils.ts b/src/urdf/UrdfUtils.ts
index 8a09d6424..63940947c 100644
--- a/src/urdf/UrdfUtils.ts
+++ b/src/urdf/UrdfUtils.ts
@@ -11,7 +11,7 @@ export function parseUrdfOrigin(originElement: Element): Pose {
     .getAttribute(UrdfAttrs.Xyz)
     ?.split(" ");
   let position: Vector3 = new Vector3();
-  if (xyz?.length === 3) {
+  if (xyz?.[0] && xyz[1] && xyz[2]) {
     position = new Vector3({
       x: parseFloat(xyz[0]),
       y: parseFloat(xyz[1]),
@@ -22,7 +22,7 @@ export function parseUrdfOrigin(originElement: Element): Pose {
   // Check the RPY
   const rpy = originElement.getAttribute(UrdfAttrs.Rpy)?.split(" ");
   let orientation = new Quaternion();
-  if (rpy?.length === 3) {
+  if (rpy?.[0] && rpy[1] && rpy[2]) {
     // Convert from RPY
     const roll = parseFloat(rpy[0]);
     const pitch = parseFloat(rpy[1]);
diff --git a/src/urdf/UrdfVisual.ts b/src/urdf/UrdfVisual.ts
index a166f1de0..17dc238d7 100644
--- a/src/urdf/UrdfVisual.ts
+++ b/src/urdf/UrdfVisual.ts
@@ -63,19 +63,19 @@ export default class UrdfVisual {
 
     // Origin
     const origins = xml.getElementsByTagName(UrdfAttrs.Origin);
-    if (origins.length > 0) {
+    if (origins[0]) {
       this.origin = parseUrdfOrigin(origins[0]);
     }
 
     // Geometry
     const geoms = xml.getElementsByTagName(UrdfAttrs.Geometry);
-    if (geoms.length > 0) {
+    if (geoms[0]) {
       this.geometry = parseUrdfGeometry(geoms[0]);
     }
 
     // Material
     const materials = xml.getElementsByTagName(UrdfAttrs.Material);
-    if (materials.length > 0) {
+    if (materials[0]) {
       this.material = new UrdfMaterial({
         xml: materials[0],
       });
diff --git a/src/util/cborTypedArrayTags.ts b/src/util/cborTypedArrayTags.ts
index ed5a18b36..ef7166e03 100644
--- a/src/util/cborTypedArrayTags.ts
+++ b/src/util/cborTypedArrayTags.ts
@@ -29,6 +29,9 @@ function decodeUint64LE(bytes: Uint8Array) {
     const si = i * 2;
     const lo = uint32View[si];
     const hi = uint32View[si + 1];
+    if (lo === undefined || hi === undefined) {
+      throw new Error("Invalid byte array");
+    }
     arr[i] = lo + UPPER32 * hi;
   }
 
@@ -55,6 +58,9 @@ function decodeInt64LE(bytes: Uint8Array) {
     const si = i * 2;
     const lo = uint32View[si];
     const hi = int32View[si + 1];
+    if (lo === undefined || hi === undefined) {
+      throw new Error("Invalid byte array");
+    }
     arr[i] = lo + UPPER32 * hi;
   }
 
@@ -120,12 +126,12 @@ export default function cborTypedArrayTagger(
   data: Uint8Array<ArrayBuffer>,
   tag: number,
 ) {
-  if (tag in nativeArrayTypes) {
-    const arrayType = nativeArrayTypes[tag];
+  const arrayType = nativeArrayTypes[tag];
+  if (arrayType) {
     return decodeNativeArray(data, arrayType);
   }
   if (tag in conversionArrayTypes) {
-    return conversionArrayTypes[tag](data);
+    return conversionArrayTypes[tag]?.(data);
   }
   return data;
 }
diff --git a/test/examples/params.example.ts b/test/examples/params.example.ts
index e3c656551..0482b6b8b 100644
--- a/test/examples/params.example.ts
+++ b/test/examples/params.example.ts
@@ -57,7 +57,7 @@ describe("Param setting", function () {
       ros.getParams(callback);
       await vi.waitFor(() => {
         expect(callback).toHaveBeenCalledOnce();
-        expect(callback.mock.calls[0][0]).to.include(PARAM_NAME);
+        expect(callback.mock.calls[0]?.[0]).to.include(PARAM_NAME);
       });
     },
   );
@@ -74,7 +74,7 @@ describe("Param setting", function () {
       const getParamsCallback = vi.fn();
       ros.getParams(getParamsCallback);
       await vi.waitFor(() =>
-        expect(getParamsCallback.mock.calls[0][0]).to.not.include(PARAM_NAME),
+        expect(getParamsCallback.mock.calls[0]?.[0]).to.not.include(PARAM_NAME),
       );
     },
   );
diff --git a/test/urdf.test.ts b/test/urdf.test.ts
index 001ca8441..6e280ad81 100644
--- a/test/urdf.test.ts
+++ b/test/urdf.test.ts
@@ -88,70 +88,68 @@ describe("URDF", function () {
       });
 
       // Check all the visual elements
-      expect(urdfModel.links["link1"].visuals.length).to.equal(1);
+      expect(urdfModel.links["link1"]?.visuals.length).to.equal(1);
       if (
-        !(urdfModel.links["link1"].visuals[0]?.geometry instanceof UrdfSphere)
+        !(urdfModel.links["link1"]?.visuals[0]?.geometry instanceof UrdfSphere)
       ) {
         throw new Error("Expected geometry to be an instance of UrdfSphere");
       }
-      expect(urdfModel.links["link1"].visuals[0]?.geometry?.radius).to.equal(
-        1.0,
-      );
-      if (!(urdfModel.links["link2"].visuals[0]?.geometry instanceof UrdfBox)) {
+      expect(urdfModel.links["link1"].visuals[0].geometry.radius).to.equal(1.0);
+      if (
+        !(urdfModel.links["link2"]?.visuals[0]?.geometry instanceof UrdfBox)
+      ) {
         throw new Error("Expected geometry to be an instance of UrdfBox");
       }
       expect(
-        urdfModel.links["link2"].visuals[0]?.geometry?.dimension?.x,
+        urdfModel.links["link2"].visuals[0].geometry.dimension?.x,
       ).to.equal(0.5);
       expect(
-        urdfModel.links["link2"].visuals[0]?.geometry?.dimension?.y,
+        urdfModel.links["link2"].visuals[0].geometry.dimension?.y,
       ).to.equal(0.5);
       expect(
-        urdfModel.links["link2"].visuals[0]?.geometry?.dimension?.z,
+        urdfModel.links["link2"].visuals[0].geometry.dimension?.z,
       ).to.equal(0.5);
       if (
-        !(urdfModel.links["link3"].visuals[0]?.geometry instanceof UrdfCylinder)
+        !(
+          urdfModel.links["link3"]?.visuals[0]?.geometry instanceof UrdfCylinder
+        )
       ) {
         throw new Error("Expected geometry to be an instance of UrdfCylinder");
       }
-      expect(urdfModel.links["link3"].visuals[0]?.geometry?.length).to.equal(
-        2.0,
-      );
-      expect(urdfModel.links["link3"].visuals[0]?.geometry?.radius).to.equal(
-        0.2,
-      );
+      expect(urdfModel.links["link3"].visuals[0].geometry.length).to.equal(2.0);
+      expect(urdfModel.links["link3"].visuals[0].geometry.radius).to.equal(0.2);
 
-      expect(urdfModel.links["link4"].visuals.length).to.equal(1);
-      expect(urdfModel.links["link4"].visuals[0]?.material?.name).to.equal(
+      expect(urdfModel.links["link4"]?.visuals.length).to.equal(1);
+      expect(urdfModel.links["link4"]?.visuals[0]?.material?.name).to.equal(
         "red",
       );
-      expect(urdfModel.links["link4"].visuals[0]?.material?.color?.r).to.equal(
+      expect(urdfModel.links["link4"]?.visuals[0]?.material?.color?.r).to.equal(
         1.0,
       );
-      expect(urdfModel.links["link4"].visuals[0]?.material?.color?.g).to.equal(
+      expect(urdfModel.links["link4"]?.visuals[0]?.material?.color?.g).to.equal(
         0,
       );
-      expect(urdfModel.links["link4"].visuals[0]?.material?.color?.b).to.equal(
+      expect(urdfModel.links["link4"]?.visuals[0]?.material?.color?.b).to.equal(
         0,
       );
-      expect(urdfModel.links["link4"].visuals[0]?.material?.color?.a).to.equal(
+      expect(urdfModel.links["link4"]?.visuals[0]?.material?.color?.a).to.equal(
         1.0,
       );
 
-      expect(urdfModel.links["link5"].visuals.length).to.equal(2);
-      expect(urdfModel.links["link5"].visuals[0]?.material?.name).to.equal(
+      expect(urdfModel.links["link5"]?.visuals.length).to.equal(2);
+      expect(urdfModel.links["link5"]?.visuals[0]?.material?.name).to.equal(
         "blue",
       );
-      expect(urdfModel.links["link5"].visuals[0]?.material?.color?.r).to.equal(
+      expect(urdfModel.links["link5"]?.visuals[0]?.material?.color?.r).to.equal(
         0.0,
       );
-      expect(urdfModel.links["link5"].visuals[0]?.material?.color?.g).to.equal(
+      expect(urdfModel.links["link5"]?.visuals[0]?.material?.color?.g).to.equal(
         0.0,
       );
-      expect(urdfModel.links["link5"].visuals[0]?.material?.color?.b).to.equal(
+      expect(urdfModel.links["link5"]?.visuals[0]?.material?.color?.b).to.equal(
         1.0,
       );
-      expect(urdfModel.links["link5"].visuals[0]?.material?.color?.a).to.equal(
+      expect(urdfModel.links["link5"]?.visuals[0]?.material?.color?.a).to.equal(
         1.0,
       );
     });
diff --git a/tsconfig.json b/tsconfig.json
index 19212b3fe..06d1bd156 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -49,11 +49,11 @@
     "strictFunctionTypes": true /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */,
     "strictPropertyInitialization": true /* Check for class properties that are declared but not set in the constructor. */,
     "noImplicitOverride": true /* Ensure overriding members in derived classes are marked with an override modifier. */,
+    "noUncheckedIndexedAccess": true /* Add `undefined` to a type when accessed using an index. */,
 
     /* Rules to be enabled */
     "exactOptionalPropertyTypes": false /* Differentiate between undefined and not present when type checking */,
     "noImplicitAny": false /* Enable error reporting for expressions and declarations with an implied 'any' type. */,
-    "noUncheckedIndexedAccess": false /* Add `undefined` to a type when accessed using an index. */,
 
     "types": ["@types/node"]
   },