diff --git a/backend/auth.py b/backend/auth.py
index eabf0af..07f499d 100644
--- a/backend/auth.py
+++ b/backend/auth.py
@@ -41,11 +41,27 @@ def _bcrypt_safe_password(password: str) -> str:
 
 
 def hash_password(password: str) -> str:
-    return pwd_context.hash(_bcrypt_safe_password(password))
+    safe = _bcrypt_safe_password(password)
+    try:
+        return pwd_context.hash(safe)
+    except Exception as e:
+        orig_len = len(password.encode("utf-8"))
+        safe_len = len(safe.encode("utf-8"))
+        raise RuntimeError(
+            f"{str(e)} (orig_bytes_len={orig_len}, safe_bytes_len={safe_len}, safe_type={type(safe).__name__})"
+        ) from e
 
 
 def verify_password(password: str, password_hash: str) -> bool:
-    return pwd_context.verify(_bcrypt_safe_password(password), password_hash)
+    safe = _bcrypt_safe_password(password)
+    try:
+        return pwd_context.verify(safe, password_hash)
+    except Exception as e:
+        orig_len = len(password.encode("utf-8"))
+        safe_len = len(safe.encode("utf-8"))
+        raise RuntimeError(
+            f"{str(e)} (orig_bytes_len={orig_len}, safe_bytes_len={safe_len}, safe_type={type(safe).__name__})"
+        ) from e
 
 
 def create_access_token(*, user_id: str) -> str: