diff --git a/src/i18n/messages/ar.json b/src/i18n/messages/ar.json
index 1834215d..cf5dd3c9 100644
--- a/src/i18n/messages/ar.json
+++ b/src/i18n/messages/ar.json
@@ -130,7 +130,7 @@
   "email.ratelimit.less.chars.validation.message": "Email must have 3 characters.",
   "username.validation.message": "Username must be between 2 and 30 characters",
   "name.validation.message": "Enter a valid name",
-  "username.format.validation.message": "Usernames can only contain letters (A-Z, a-z), numerals (0-9), underscores (_), and hyphens (-).",
+  "username.format.validation.message": "Usernames can only contain letters (A-Z, a-z), numerals (0-9), underscores (_), and hyphens (-). Usernames cannot contain spaces.",
   "support.education.research": "Support education research by providing additional information. (Optional)",
   "registration.request.failure.header": "We couldn't create your account.",
   "registration.empty.form.submission.error": "Please check your responses and try again.",
diff --git a/src/i18n/messages/es_419.json b/src/i18n/messages/es_419.json
index 89df0155..97d12a5d 100644
--- a/src/i18n/messages/es_419.json
+++ b/src/i18n/messages/es_419.json
@@ -130,7 +130,7 @@
   "email.ratelimit.less.chars.validation.message": "El correo electrónico debe tener 3 caracteres.",
   "username.validation.message": "El nombre de usuario debe tener entre 2 y 30 caracteres",
   "name.validation.message": "Introduce un nombre válido",
-  "username.format.validation.message": "Los nombres de usuario únicamente pueden contener las letras (A-Z, a-z), números (0-9), guión bajo (_) y guiones (-).",
+  "username.format.validation.message": "Usernames can only contain letters (A-Z, a-z), numerals (0-9), underscores (_), and hyphens (-). Usernames cannot contain spaces.",
   "support.education.research": "Apoya la investigación sobre educación proporcionando información adicional. (Opcional)",
   "registration.request.failure.header": "No pudimos crear tu cuenta.",
   "registration.empty.form.submission.error": "Por favor, verifica tus respuestas y vuelve a intentarlo.",
diff --git a/src/i18n/messages/fr.json b/src/i18n/messages/fr.json
index aac32b17..20ebdb8b 100644
--- a/src/i18n/messages/fr.json
+++ b/src/i18n/messages/fr.json
@@ -130,7 +130,7 @@
   "email.ratelimit.less.chars.validation.message": "Email must have 3 characters.",
   "username.validation.message": "Username must be between 2 and 30 characters",
   "name.validation.message": "Enter a valid name",
-  "username.format.validation.message": "Usernames can only contain letters (A-Z, a-z), numerals (0-9), underscores (_), and hyphens (-).",
+  "username.format.validation.message": "Usernames can only contain letters (A-Z, a-z), numerals (0-9), underscores (_), and hyphens (-). Usernames cannot contain spaces.",
   "support.education.research": "Support education research by providing additional information. (Optional)",
   "registration.request.failure.header": "We couldn't create your account.",
   "registration.empty.form.submission.error": "Please check your responses and try again.",
diff --git a/src/i18n/messages/zh_CN.json b/src/i18n/messages/zh_CN.json
index aac32b17..20ebdb8b 100644
--- a/src/i18n/messages/zh_CN.json
+++ b/src/i18n/messages/zh_CN.json
@@ -130,7 +130,7 @@
   "email.ratelimit.less.chars.validation.message": "Email must have 3 characters.",
   "username.validation.message": "Username must be between 2 and 30 characters",
   "name.validation.message": "Enter a valid name",
-  "username.format.validation.message": "Usernames can only contain letters (A-Z, a-z), numerals (0-9), underscores (_), and hyphens (-).",
+  "username.format.validation.message": "Usernames can only contain letters (A-Z, a-z), numerals (0-9), underscores (_), and hyphens (-). Usernames cannot contain spaces.",
   "support.education.research": "Support education research by providing additional information. (Optional)",
   "registration.request.failure.header": "We couldn't create your account.",
   "registration.empty.form.submission.error": "Please check your responses and try again.",