diff --git a/src/Typesense/Aliases.ts b/src/Typesense/Aliases.ts
index 0b3942e0..786ec541 100644
--- a/src/Typesense/Aliases.ts
+++ b/src/Typesense/Aliases.ts
@@ -31,7 +31,7 @@ export default class Aliases {
     return this.apiCall.get<CollectionAliasesResponseSchema>(RESOURCEPATH);
   }
 
-  private endpointPath(aliasName): string {
+  private endpointPath(aliasName: string): string {
     return `${Aliases.RESOURCEPATH}/${aliasName}`;
   }
 
diff --git a/src/Typesense/ApiCall.ts b/src/Typesense/ApiCall.ts
index b56c2115..537c7b2a 100644
--- a/src/Typesense/ApiCall.ts
+++ b/src/Typesense/ApiCall.ts
@@ -19,6 +19,7 @@ const UNHEALTHY = false;
 interface Node extends NodeConfiguration {
   isHealthy: boolean;
   index: string | number;
+  lastAccessTimestamp: number;
 }
 
 export default class ApiCall {
@@ -340,7 +341,7 @@ export default class ApiCall {
     return candidateNode;
   }
 
-  nodeDueForHealthcheck(node, requestNumber = 0): boolean {
+  nodeDueForHealthcheck(node: Node, requestNumber = 0): boolean {
     const isDueForHealthcheck =
       Date.now() - node.lastAccessTimestamp >
       this.healthcheckIntervalSeconds * 1000;
@@ -364,12 +365,12 @@ export default class ApiCall {
     });
   }
 
-  setNodeHealthcheck(node, isHealthy): void {
+  setNodeHealthcheck(node: Node, isHealthy: boolean): void {
     node.isHealthy = isHealthy;
     node.lastAccessTimestamp = Date.now();
   }
 
-  uriFor(endpoint: string, node): string {
+  uriFor(endpoint: string, node: NodeConfiguration): string {
     if (node.url != null) {
       return `${node.url}${endpoint}`;
     }
@@ -377,7 +378,7 @@ export default class ApiCall {
   }
 
   defaultHeaders(): any {
-    const defaultHeaders = {};
+    const defaultHeaders: Record<string, string> = {};
     if (!this.sendApiKeyAsQueryParam) {
       defaultHeaders[APIKEYHEADERNAME] = this.apiKey;
     }
@@ -385,7 +386,7 @@ export default class ApiCall {
     return defaultHeaders;
   }
 
-  async timer(seconds): Promise<void> {
+  async timer(seconds: number): Promise<void> {
     return new Promise((resolve) => setTimeout(resolve, seconds * 1000));
   }
 
diff --git a/src/Typesense/Configuration.ts b/src/Typesense/Configuration.ts
index cdbcdb5d..efc7f221 100644
--- a/src/Typesense/Configuration.ts
+++ b/src/Typesense/Configuration.ts
@@ -2,25 +2,28 @@ import * as logger from "loglevel";
 import { Logger, LogLevelDesc } from "loglevel";
 import { MissingConfigurationError } from "./Errors";
 
-export interface NodeConfiguration {
+export interface NodeConfigurationWithHostname {
   host: string;
   port: number;
   protocol: string;
   path?: string;
-  url?: string;
 }
 
-export interface NodeConfigurationWithHostname {
-  host: string;
-  port: number;
-  protocol: string;
-  path?: string;
+export interface NodeConfiguration extends NodeConfigurationWithHostname {
+  url?: string;
 }
 
 export interface NodeConfigurationWithUrl {
   url: string;
 }
 
+type NodeType = NodeConfiguration | NodeConfigurationWithHostname | NodeConfigurationWithUrl | undefined;
+
+
+function isNodeConfigurationWithHostname(node: NodeType): node is NodeConfigurationWithHostname {
+    return node !== undefined && (node as NodeConfigurationWithHostname).protocol !== undefined;
+}
+
 export interface ConfigurationOptions {
   apiKey: string;
   nodes:
@@ -166,49 +169,29 @@ export default class Configuration {
     return (
       !["protocol", "host", "port", "path"].every((key) => {
         return node.hasOwnProperty(key);
-      }) && node["url"] == null
+      }) && node.hasOwnProperty("url") == null
     );
   }
 
   private setDefaultPathInNode(
-    node:
-      | NodeConfiguration
-      | NodeConfigurationWithHostname
-      | NodeConfigurationWithUrl
-      | undefined
-  ):
-    | NodeConfiguration
-    | NodeConfigurationWithHostname
-    | NodeConfigurationWithUrl
-    | undefined {
-    if (node != null && !node.hasOwnProperty("path")) {
-      node["path"] = "";
-    }
+    node: NodeType
+  ): NodeType {
+      if (isNodeConfigurationWithHostname(node)) {
+	node.path = "";
+      }
     return node;
   }
 
   private setDefaultPortInNode(
-    node:
-      | NodeConfiguration
-      | NodeConfigurationWithHostname
-      | NodeConfigurationWithUrl
-      | undefined
-  ):
-    | NodeConfiguration
-    | NodeConfigurationWithHostname
-    | NodeConfigurationWithUrl
-    | undefined {
-    if (
-      node != null &&
-      !node.hasOwnProperty("port") &&
-      node.hasOwnProperty("protocol")
-    ) {
-      switch (node["protocol"]) {
+    node: NodeType
+  ): NodeType {
+      if (isNodeConfigurationWithHostname(node)) {
+      switch (node.protocol) {
         case "https":
-          node["port"] = 443;
+          node.port = 443;
           break;
         case "http":
-          node["port"] = 80;
+          node.port = 80;
           break;
       }
     }
@@ -233,7 +216,7 @@ export default class Configuration {
     }
   }
 
-  private shuffleArray(array) {
+  private shuffleArray(array: object[]) {
     for (let i = array.length - 1; i > 0; i--) {
       const j = Math.floor(Math.random() * (i + 1));
       [array[i], array[j]] = [array[j], array[i]];
diff --git a/src/Typesense/Documents.ts b/src/Typesense/Documents.ts
index 48415391..acb3649d 100644
--- a/src/Typesense/Documents.ts
+++ b/src/Typesense/Documents.ts
@@ -248,7 +248,8 @@ export default class Documents<T extends DocumentSchema = object>
   ): Promise<UpdateByFilterResponse | T> {
     if (!document) throw new Error("No document provided");
 
-    if (options["filter_by"] != null) {
+    // @ts-expect-error filter_by does not exist in options
+    if (options ["filter_by"] != null) {
       return this.apiCall.patch<T>(
         this.endpointPath(),
         document,
diff --git a/src/Typesense/Errors/ImportError.ts b/src/Typesense/Errors/ImportError.ts
index 94ffe3e9..f9934725 100644
--- a/src/Typesense/Errors/ImportError.ts
+++ b/src/Typesense/Errors/ImportError.ts
@@ -1,9 +1,9 @@
 import TypesenseError from "./TypesenseError";
-import { ImportResponseFail } from "../Documents";
+import { ImportResponseFail, ImportResponse } from "../Documents";
 
 export default class ImportError extends TypesenseError {
-  importResults: ImportResponseFail;
-  constructor(message, importResults) {
+  importResults: ImportResponseFail | ImportResponse[];
+  constructor(message: string, importResults: ImportResponseFail | ImportResponse[]) {
     super(message);
     this.importResults = importResults;
   }
diff --git a/src/Typesense/MultiSearch.ts b/src/Typesense/MultiSearch.ts
index 036de8df..7cab0bb6 100644
--- a/src/Typesense/MultiSearch.ts
+++ b/src/Typesense/MultiSearch.ts
@@ -54,12 +54,12 @@ export default class MultiSearch {
         .cacheSearchResultsForSeconds,
     }: { cacheSearchResultsForSeconds?: number } = {}
   ): Promise<MultiSearchResponse<T>> {
-    const additionalHeaders = {};
+    const additionalHeaders: Record<string, string> = {};
     if (this.useTextContentType) {
       additionalHeaders["content-type"] = "text/plain";
     }
 
-    const additionalQueryParams = {};
+    const additionalQueryParams: Record<string, boolean> = {};
     if (this.configuration.useServerSideSearchCache === true) {
       additionalQueryParams["use_cache"] = true;
     }
diff --git a/src/Typesense/SearchOnlyDocuments.ts b/src/Typesense/SearchOnlyDocuments.ts
index 5efb68fc..ab177c13 100644
--- a/src/Typesense/SearchOnlyDocuments.ts
+++ b/src/Typesense/SearchOnlyDocuments.ts
@@ -36,12 +36,14 @@ export class SearchOnlyDocuments<T extends DocumentSchema>
       abortSignal = null,
     }: SearchOptions = {}
   ): Promise<SearchResponse<T>> {
-    const additionalQueryParams = {};
+    const additionalQueryParams: Record<string, boolean> = {};
     if (this.configuration.useServerSideSearchCache === true) {
       additionalQueryParams["use_cache"] = true;
     }
     for (const key in searchParameters) {
+      // @ts-expect-error allow random lookup
       if (Array.isArray(searchParameters[key])) {
+	// @ts-expect-error allow random lookup
         additionalQueryParams[key] = searchParameters[key].join(",");
       }
     }
diff --git a/tsconfig.json b/tsconfig.json
index 7938271c..70f9bc8c 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -27,7 +27,7 @@
 
         /* Strict Type-Checking Options */
         "strict": true /* Enable all strict type-checking options. */,
-        "noImplicitAny": false /* Raise error on expressions and declarations with an implied 'any' type. */,
+        "noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,
         // "strictNullChecks": true,              /* Enable strict null checks. */
         // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
         // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */