diff --git a/src/launch_config.rs b/src/launch_config.rs
index 7a26c29..708b7c9 100644
--- a/src/launch_config.rs
+++ b/src/launch_config.rs
@@ -136,7 +136,7 @@ impl LauncherConfig {
         if let Some(mem_per) = self.max_mem_percent {
             let has_xmx = out.iter().any(|s| s.starts_with("-Xmx"));
             if !has_xmx {
-                out.push(format!("-Xmx{}k", get_max_heap(mem_per)))
+                out.push(format!("-Xmx{}m", (get_max_heap(mem_per)) / 1000))
             }
         }