diff --git a/src/components/views/right_panel/UserInfo.js b/src/components/views/right_panel/UserInfo.js
index 53a87ed1c6..41eb723c79 100644
--- a/src/components/views/right_panel/UserInfo.js
+++ b/src/components/views/right_panel/UserInfo.js
@@ -1027,10 +1027,13 @@ const UserInfo = withLegacyMatrixClient(({matrixClient: cli, user, groupId, room
         const [accepted] = await finished;
         if (!accepted) return;
         try {
-            cli.deactivateSynapseUser(user.userId);
+            await cli.deactivateSynapseUser(user.userId);
         } catch (err) {
+            console.error("Failed to deactivate user");
+            console.error(err);
+
             const ErrorDialog = sdk.getComponent('dialogs.ErrorDialog');
-            Modal.createTrackedDialog('Failed to deactivate user', '', ErrorDialog, {
+            Modal.createTrackedDialog('Failed to deactivate Synapse user', '', ErrorDialog, {
                 title: _t('Failed to deactivate user'),
                 description: ((err && err.message) ? err.message : _t("Operation failed")),
             });
diff --git a/src/components/views/rooms/MemberInfo.js b/src/components/views/rooms/MemberInfo.js
index 2ea6392e96..9364f2f49d 100644
--- a/src/components/views/rooms/MemberInfo.js
+++ b/src/components/views/rooms/MemberInfo.js
@@ -550,7 +550,16 @@ module.exports = createReactClass({
             danger: true,
             onFinished: (accepted) => {
                 if (!accepted) return;
-                this.context.matrixClient.deactivateSynapseUser(this.props.member.userId);
+                this.context.matrixClient.deactivateSynapseUser(this.props.member.userId).catch(e => {
+                    console.error("Failed to deactivate user");
+                    console.error(e);
+
+                    const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
+                    Modal.createTrackedDialog('Failed to deactivate Synapse user', '', ErrorDialog, {
+                        title: _t('Failed to deactivate user'),
+                        description: ((e && e.message) ? e.message : _t("Operation failed")),
+                    });
+                });
             },
         });
     },
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index a90af471c2..655c7030c4 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -868,6 +868,7 @@
     "Deactivate user?": "Deactivate user?",
     "Deactivating this user will log them out and prevent them from logging back in. Additionally, they will leave all the rooms they are in. This action cannot be reversed. Are you sure you want to deactivate this user?": "Deactivating this user will log them out and prevent them from logging back in. Additionally, they will leave all the rooms they are in. This action cannot be reversed. Are you sure you want to deactivate this user?",
     "Deactivate user": "Deactivate user",
+    "Failed to deactivate user": "Failed to deactivate user",
     "Failed to change power level": "Failed to change power level",
     "You will not be able to undo this change as you are promoting the user to have the same power level as yourself.": "You will not be able to undo this change as you are promoting the user to have the same power level as yourself.",
     "Are you sure?": "Are you sure?",
@@ -1081,7 +1082,6 @@
     "Failed to withdraw invitation": "Failed to withdraw invitation",
     "Failed to remove user from community": "Failed to remove user from community",
     "<strong>%(role)s</strong> in %(roomName)s": "<strong>%(role)s</strong> in %(roomName)s",
-    "Failed to deactivate user": "Failed to deactivate user",
     "This client does not support end-to-end encryption.": "This client does not support end-to-end encryption.",
     "Messages in this room are not end-to-end encrypted.": "Messages in this room are not end-to-end encrypted.",
     "Messages in this room are end-to-end encrypted.": "Messages in this room are end-to-end encrypted.",