diff --git a/capsulflask/virt_model.py b/capsulflask/virt_model.py
index 4aa321a..e6b09e9 100644
--- a/capsulflask/virt_model.py
+++ b/capsulflask/virt_model.py
@@ -70,7 +70,7 @@ class ShellScriptVirtualization(VirtualizationInterface):
       """)
 
   def capacity_avaliable(self, additional_ram_bytes):
-    my_args=[join(current_app.root_path, 'shell_scripts/capacity-avaliable.sh'), additional_ram_bytes]
+    my_args=[join(current_app.root_path, 'shell_scripts/capacity-avaliable.sh'), str(additional_ram_bytes)]
     completedProcess = run(my_args, capture_output=True)
 
     if completedProcess.returncode != 0: