diff --git a/src/inference.rs b/src/inference.rs
index ffd3e73..ea30b69 100644
--- a/src/inference.rs
+++ b/src/inference.rs
@@ -16,11 +16,31 @@ pub struct SimulateSubcommand {
 	gpu_id: Option<usize>,
 	#[arg(long)]
 	model_path: std::path::PathBuf,
+	#[arg(long)]
+	output_file: Option<std::path::PathBuf>,
 }
 
 impl SimulateSubcommand {
 	fn run(self) {
-		inference(self.gpu_id.unwrap_or_default(), self.model_path);
+		let output_file = self.output_file.unwrap_or_else(|| {
+			let mut file_name = self
+				.model_path
+				.file_stem()
+				.unwrap()
+				.to_str()
+				.unwrap()
+				.to_owned();
+			file_name.push_str("_replay");
+			let mut path = self.model_path.clone();
+			path.set_file_name(file_name);
+			path.set_extension("snfb");
+			path
+		});
+		inference(
+			self.gpu_id.unwrap_or_default(),
+			self.model_path,
+			output_file,
+		);
 	}
 }
 
@@ -79,7 +99,7 @@ impl Session {
 	}
 }
 
-fn inference(gpu_id: usize, model_path: std::path::PathBuf) {
+fn inference(gpu_id: usize, model_path: std::path::PathBuf, output_file: std::path::PathBuf) {
 	// pick device
 	let device = burn::backend::cuda::CudaDevice::new(gpu_id);
 
@@ -206,8 +226,7 @@ fn inference(gpu_id: usize, model_path: std::path::PathBuf) {
 		input_floats.clear();
 	}
 
-	let date_string = format!("{}.snfb", chrono::Utc::now());
-	let file = std::fs::File::create(date_string).unwrap();
+	let file = std::fs::File::create(output_file).unwrap();
 	strafesnet_snf::bot::write_bot(
 		std::io::BufWriter::new(file),
 		strafesnet_physics::VERSION.get(),