diff --git a/src/ui/login-form-ui-handler.ts b/src/ui/login-form-ui-handler.ts
index c7268019f29..ce6a28b5290 100644
--- a/src/ui/login-form-ui-handler.ts
+++ b/src/ui/login-form-ui-handler.ts
@@ -62,7 +62,7 @@ export default class LoginFormUiHandler extends FormModalUiHandler {
         const headers = {
           'Content-Type': contentType,
         };
-        fetch(`${Utils.apiUrl}/account/login`, { method: 'POST', headers: headers, body: `username=${this.inputs[0].text}&password=${this.inputs[1].text}` })
+        fetch(`${Utils.apiUrl}/account/login`, { method: 'POST', headers: headers, body: `username=${encodeURIComponent(this.inputs[0].text)}&password=${encodeURIComponent(this.inputs[1].text)}` })
           .then(response => {
             if (!response.ok)
               return response.text();
diff --git a/src/ui/registration-form-ui-handler.ts b/src/ui/registration-form-ui-handler.ts
index 93dcf5f5910..d15df22bd85 100644
--- a/src/ui/registration-form-ui-handler.ts
+++ b/src/ui/registration-form-ui-handler.ts
@@ -77,11 +77,11 @@ export default class RegistrationFormUiHandler extends FormModalUiHandler {
         const headers = {
           'Content-Type': contentType,
         };
-        fetch(`${Utils.apiUrl}/account/register`, { method: 'POST', headers: headers, body: `username=${this.inputs[0].text}&password=${this.inputs[1].text}` })
+        fetch(`${Utils.apiUrl}/account/register`, { method: 'POST', headers: headers, body: `username=${encodeURIComponent(this.inputs[0].text)}&password=${encodeURIComponent(this.inputs[1].text)}` })
           .then(response => response.text())
           .then(response => {
             if (!response) {
-              fetch(`${Utils.apiUrl}/account/login`, { method: 'POST', headers: headers, body: `username=${this.inputs[0].text}&password=${this.inputs[1].text}` })
+              fetch(`${Utils.apiUrl}/account/login`, { method: 'POST', headers: headers, body: `username=${encodeURIComponent(this.inputs[0].text)}&password=${encodeURIComponent(this.inputs[1].text)}` })
                 .then(response => {
                   if (!response.ok)
                     return response.text();