diff --git a/backend/open_webui/constants.py b/backend/open_webui/constants.py
index 86d87a2c3..95c54a0d2 100644
--- a/backend/open_webui/constants.py
+++ b/backend/open_webui/constants.py
@@ -31,6 +31,7 @@ class ERROR_MESSAGES(str, Enum):
     USERNAME_TAKEN = (
         "Uh-oh! This username is already registered. Please choose another username."
     )
+    PASSWORD_TOO_LONG = "Uh-oh! The password you entered is too long. Please make sure your password is less than 72 bytes long."
     COMMAND_TAKEN = "Uh-oh! This command is already registered. Please choose another command string."
     FILE_EXISTS = "Uh-oh! This file is already registered. Please choose another file."
 
diff --git a/backend/open_webui/routers/auths.py b/backend/open_webui/routers/auths.py
index 67c2e9f2a..7905799e6 100644
--- a/backend/open_webui/routers/auths.py
+++ b/backend/open_webui/routers/auths.py
@@ -454,6 +454,13 @@ async def signup(request: Request, response: Response, form_data: SignupForm):
             # Disable signup after the first user is created
             request.app.state.config.ENABLE_SIGNUP = False
 
+        # The password passed to bcrypt must be 72 bytes or fewer. If it is longer, it will be truncated before hashing.
+        if len(form_data.password.encode("utf-8")) > 72:
+            raise HTTPException(
+                status.HTTP_400_BAD_REQUEST,
+                detail=ERROR_MESSAGES.PASSWORD_TOO_LONG,
+            )
+
         hashed = get_password_hash(form_data.password)
         user = Auths.insert_new_auth(
             form_data.email.lower(),