diff --git a/backends/trtllm/src/backend.rs b/backends/trtllm/src/backend.rs
index 1f94fd3a..5e7a2098 100644
--- a/backends/trtllm/src/backend.rs
+++ b/backends/trtllm/src/backend.rs
@@ -20,7 +20,9 @@ use tracing::{instrument, Level, span};
 
 use text_generation_router::{FinishReason, Token};
 use text_generation_router::infer::{Backend, GeneratedText, InferError, InferStreamResponse};
-use text_generation_router::validation::{Chunk, ValidationError, ValidGenerateRequest};
+use text_generation_router::validation::{
+    Chunk, ValidationError, ValidGenerateRequest, ValidParameters,
+};
 use text_generation_router::validation::ValidationError::UnsupportedModality;
 
 use crate::errors::TensorRtLlmBackendError;
@@ -121,6 +123,11 @@ impl TensorRtLlmBackend {
             ));
         }
 
+        // TODO: Is it really needed? How can it be validated before?
+        if request.parameters.grammar.is_some() {
+            return Err(InferError::ValidationError(ValidationError::Grammar));
+        }
+
         match request.inputs.len() {
             0 => Err(InferError::ValidationError(ValidationError::EmptyInput)),
             2.. => Err(InferError::GenerationError(
@@ -308,6 +315,8 @@ impl Backend for TensorRtLlmBackend {
             params.top_k,
             params.top_p,
             params.temperature,
+            params.repetition_penalty,
+            params.frequency_penalty,
             params.seed,
         );