diff --git a/packages/web-api/src/WebClient.spec.js b/packages/web-api/src/WebClient.spec.js
index 3320a6363..60fa8a413 100644
--- a/packages/web-api/src/WebClient.spec.js
+++ b/packages/web-api/src/WebClient.spec.js
@@ -227,6 +227,57 @@ describe('WebClient', function () {
             });
         });
       });
+
+      const threadTsTestPatterns = [
+        { method: 'chat.postEphemeral' },
+        { method: 'chat.postMessage' },
+        { method: 'chat.scheduleMessage' },
+        { method: 'files.upload' },
+      ];
+
+      threadTsTestPatterns.reduce((acc, { method, args }) => {
+        const threadTs = [{ thread_ts: 1503435956.000247, text: 'text' }]
+          .map(v => ({ method, args: Object.assign({}, v, args) }))
+        return acc.concat(threadTs)
+      }, []).forEach(({ method, args }) => {
+        it(`should send warning to logs when thread_ts in ${method} arguments is a float`, function () {
+          const logger = {
+            debug: sinon.spy(),
+            info: sinon.spy(),
+            warn: sinon.spy(),
+            error: sinon.spy(),
+            setLevel: sinon.spy(),
+            setName: sinon.spy(),
+          };
+          const warnClient = new WebClient(token, { logLevel: LogLevel.WARN, logger });
+          return warnClient.apiCall(method, args)
+            .then(() => {
+              assert.isTrue(logger.warn.callCount === 4);
+            });
+        });
+      });
+
+      threadTsTestPatterns.reduce((acc, { method, args }) => {
+        const threadTs = [{ thread_ts: '1503435956.000247', text: 'text' }]
+          .map(v => ({ method, args: Object.assign({}, v, args) }))
+        return acc.concat(threadTs)
+      }, []).forEach(({ method, args }) => {
+        it(`should not send warning to logs when thread_ts in ${method} arguments is a string`, function () {
+          const logger = {
+            debug: sinon.spy(),
+            info: sinon.spy(),
+            warn: sinon.spy(),
+            error: sinon.spy(),
+            setLevel: sinon.spy(),
+            setName: sinon.spy(),
+          };
+          const warnClient = new WebClient(token, { logLevel: LogLevel.WARN, logger });
+          return warnClient.apiCall(method, args)
+            .then(() => {
+              assert.isTrue(logger.warn.calledThrice);
+            });
+        });
+      });
     });
 
     describe('with OAuth scopes in the response headers', function () {
diff --git a/packages/web-api/src/WebClient.ts b/packages/web-api/src/WebClient.ts
index 45ffaa435..9f5a01dc2 100644
--- a/packages/web-api/src/WebClient.ts
+++ b/packages/web-api/src/WebClient.ts
@@ -156,6 +156,7 @@ export class WebClient extends Methods {
 
     warnDeprecations(method, this.logger);
     warnIfFallbackIsMissing(method, this.logger, options);
+    warnIfThreadTsIsNotString(method, this.logger, options);
 
     if (typeof options === 'string' || typeof options === 'number' || typeof options === 'boolean') {
       throw new TypeError(`Expected an options argument but instead received a ${typeof options}`);
@@ -619,6 +620,7 @@ function warnDeprecations(method: string, logger: Logger): void {
  * Log a warning when using chat.postMessage without text argument or attachments with fallback argument
  * @param method api method being called
  * @param logger instance of we clients logger
+ * @param options arguments for the Web API method
  */
 function warnIfFallbackIsMissing(method: string, logger: Logger, options?: WebAPICallOptions): void {
   const targetMethods = ['chat.postEphemeral', 'chat.postMessage', 'chat.scheduleMessage', 'chat.update'];
@@ -645,3 +647,18 @@ function warnIfFallbackIsMissing(method: string, logger: Logger, options?: WebAP
     }
   }
 }
+
+/**
+ * Log a warning when thread_ts is not a string
+ * @param method api method being called
+ * @param logger instance of web clients logger
+ * @param options arguments for the Web API method
+ */
+function warnIfThreadTsIsNotString(method: string, logger: Logger, options?: WebAPICallOptions): void {
+  const targetMethods = ['chat.postEphemeral', 'chat.postMessage', 'chat.scheduleMessage', 'files.upload'];
+  const isTargetMethod = targetMethods.includes(method);
+
+  if (isTargetMethod && options?.thread_ts !== undefined && typeof options?.thread_ts !== 'string') {
+    logger.warn(`The given thread_ts value in the request payload for a ${method} call is a float value. We highly recommend using a string value instead.`);
+  }
+}