Fixes #42 - Requests with spaces fail to generate correct signature
diff --git a/ec2stack/helpers.py b/ec2stack/helpers.py
index 78c4b36..08a80d2 100644
--- a/ec2stack/helpers.py
+++ b/ec2stack/helpers.py
@@ -185,6 +185,8 @@
         )
     )
 
+    query_string = query_string.replace('+', '%20')
+
     return query_string