diff --git a/src/components/views/dialogs/CreateGroupDialog.js b/src/components/views/dialogs/CreateGroupDialog.js
index 6e14d1cf66..882d323449 100644
--- a/src/components/views/dialogs/CreateGroupDialog.js
+++ b/src/components/views/dialogs/CreateGroupDialog.js
@@ -57,7 +57,7 @@ export default React.createClass({
         let error = null;
         if (!this.state.groupId) {
             error = _t("Community IDs cannot be empty.");
-        } else if (!/^[a-z0-9=_\-\.\/]*$/.test(this.state.groupId)) {
+        } else if (!/^[a-z0-9=_\-./]*$/.test(this.state.groupId)) {
             error = _t("Community IDs may only contain characters a-z, 0-9, or '=_-./'");
         }
         this.setState({
diff --git a/src/components/views/elements/Pill.js b/src/components/views/elements/Pill.js
index af7e8c4ae3..0d0949f07c 100644
--- a/src/components/views/elements/Pill.js
+++ b/src/components/views/elements/Pill.js
@@ -29,7 +29,7 @@ const REGEX_MATRIXTO = new RegExp(MATRIXTO_URL_PATTERN);
 
 // For URLs of matrix.to links in the timeline which have been reformatted by
 // HttpUtils transformTags to relative links. This excludes event URLs (with `[^\/]*`)
-const REGEX_LOCAL_MATRIXTO = /^#\/(?:user|room|group)\/(([#!@+])[^\/]*)$/;
+const REGEX_LOCAL_MATRIXTO = /^#\/(?:user|room|group)\/(([#!@+])[^/]*)$/;
 
 const Pill = React.createClass({
     statics: {
diff --git a/src/components/views/room_settings/RelatedGroupSettings.js b/src/components/views/room_settings/RelatedGroupSettings.js
index 65132b9b74..4bad5ca806 100644
--- a/src/components/views/room_settings/RelatedGroupSettings.js
+++ b/src/components/views/room_settings/RelatedGroupSettings.js
@@ -22,7 +22,7 @@ import { _t } from '../../../languageHandler';
 import Modal from '../../../Modal';
 import isEqual from 'lodash/isEqual';
 
-const GROUP_ID_REGEX = /\+\S+\:\S+/;
+const GROUP_ID_REGEX = /\+\S+:\S+/;
 
 module.exports = React.createClass({
     displayName: 'RelatedGroupSettings',
diff --git a/src/phonenumber.js b/src/phonenumber.js
index aaf018ba26..3b7e4ba4f1 100644
--- a/src/phonenumber.js
+++ b/src/phonenumber.js
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-const PHONE_NUMBER_REGEXP = /^[0-9 -\.]+$/;
+const PHONE_NUMBER_REGEXP = /^[0-9 -.]+$/;
 
 /*
  * Do basic validation to determine if the given input could be