diff --git a/core/src/main/java/org/springframework/security/authentication/ott/OneTimeTokenAuthenticationProvider.java b/core/src/main/java/org/springframework/security/authentication/ott/OneTimeTokenAuthenticationProvider.java
index 5ec5893077..361e1f06d7 100644
--- a/core/src/main/java/org/springframework/security/authentication/ott/OneTimeTokenAuthenticationProvider.java
+++ b/core/src/main/java/org/springframework/security/authentication/ott/OneTimeTokenAuthenticationProvider.java
@@ -62,7 +62,7 @@ public final class OneTimeTokenAuthenticationProvider implements AuthenticationP
 			return authenticated;
 		}
 		catch (UsernameNotFoundException ex) {
-			throw new BadCredentialsException("Authentication failed.");
+			throw new BadCredentialsException("Failed to authenticate the one-time token");
 		}
 	}