diff --git a/src/CONST.js b/src/CONST.js
index 9d6f7dcf2a4c..cbf24bae5610 100755
--- a/src/CONST.js
+++ b/src/CONST.js
@@ -15,6 +15,9 @@ const CONST = {
     ANIMATION_IN_TIMING: 100,
 
     API_ATTACHMENT_VALIDATIONS: {
+        // Same as the PHP layer allows
+        ALLOWED_EXTENSIONS: ['jpg', 'jpeg', 'png', 'gif', 'pdf', 'html', 'txt', 'rtf', 'doc', 'docx', 'htm', 'tiff', 'tif', 'xml', 'mp3', 'mp4', 'mov'],
+
         // 50 megabytes in bytes
         MAX_SIZE: 52428800,
 
diff --git a/src/components/AttachmentModal.js b/src/components/AttachmentModal.js
index bb79652e975c..4e0f31c53485 100755
--- a/src/components/AttachmentModal.js
+++ b/src/components/AttachmentModal.js
@@ -4,6 +4,7 @@ import {View, Animated, Keyboard} from 'react-native';
 import Str from 'expensify-common/lib/str';
 import lodashGet from 'lodash/get';
 import lodashExtend from 'lodash/extend';
+import _ from 'underscore';
 import CONST from '../CONST';
 import Modal from './Modal';
 import AttachmentView from './AttachmentView';
@@ -168,6 +169,17 @@ class AttachmentModal extends PureComponent {
             return false;
         }
 
+        const {fileExtension} = FileUtils.splitExtensionFromFileName(lodashGet(file, 'name', ''));
+        if (!_.contains(CONST.API_ATTACHMENT_VALIDATIONS.ALLOWED_EXTENSIONS, fileExtension.toLowerCase())) {
+            const invalidReason = `${this.props.translate('attachmentPicker.notAllowedExtension')} ${CONST.API_ATTACHMENT_VALIDATIONS.ALLOWED_EXTENSIONS.join(', ')}`;
+            this.setState({
+                isAttachmentInvalid: true,
+                attachmentInvalidReasonTitle: this.props.translate('attachmentPicker.wrongFileType'),
+                attachmentInvalidReason: invalidReason,
+            });
+            return false;
+        }
+
         return true;
     }