diff --git a/launcher/src/main.rs b/launcher/src/main.rs
index a4bb2e3d..3f1b37d6 100644
--- a/launcher/src/main.rs
+++ b/launcher/src/main.rs
@@ -22,7 +22,8 @@ mod env_runtime;
 
 #[derive(Deserialize)]
 struct Config {
-    max_position_embeddings: usize,
+    max_position_embeddings: Option<usize>,
+    max_seq_len: Option<usize>,
 }
 
 #[derive(Clone, Copy, Debug, ValueEnum)]
@@ -817,6 +818,14 @@ enum LauncherError {
     WebserverCannotStart,
 }
 
+impl core::fmt::Display for LauncherError {
+    fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+        write!(f, "{self:?}")
+    }
+}
+
+impl std::error::Error for LauncherError {}
+
 fn download_convert_model(args: &Args, running: Arc<AtomicBool>) -> Result<(), LauncherError> {
     // Enter download tracing span
     let _span = tracing::span!(tracing::Level::INFO, "download").entered();
@@ -1291,12 +1300,21 @@ fn main() -> Result<(), LauncherError> {
             2usize.pow(14)
         };
 
-        let max_position_embeddings = if config.max_position_embeddings > max_default {
-            let max = config.max_position_embeddings;
-            tracing::info!("Model supports up to {max} but tgi will now set its default to {max_default} instead. This is to save VRAM by refusing large prompts in order to allow more users on the same hardware. You can increase that size using `--max-batch-prefill-tokens={} --max-total-tokens={max} --max-input-tokens={}`.", max - 1, max - 1);
-            max_default
-        } else {
-            config.max_position_embeddings
+        let max_position_embeddings = match (config.max_position_embeddings, config.max_seq_len) {
+            (Some(max_position_embeddings), _) | (None, Some(max_position_embeddings)) => {
+                if max_position_embeddings > max_default {
+                    let max = max_position_embeddings;
+                    tracing::info!("Model supports up to {max} but tgi will now set its default to {max_default} instead. This is to save VRAM by refusing large prompts in order to allow more users on the same hardware. You can increase that size using `--max-batch-prefill-tokens={} --max-total-tokens={max} --max-input-tokens={}`.", max + 50, max - 1);
+                    max_default
+                } else {
+                    max_position_embeddings
+                }
+            }
+            _ => {
+                return Err(Box::new(LauncherError::ArgumentValidation(
+                    "no max defined".to_string(),
+                )));
+            }
         };
         Ok(max_position_embeddings)
     };