diff --git a/distillery/resources/compose/triplestore/docker-compose.yml b/distillery/resources/compose/triplestore/docker-compose.yml
index 0562fcf..8a89970 100644
--- a/distillery/resources/compose/triplestore/docker-compose.yml
+++ b/distillery/resources/compose/triplestore/docker-compose.yml
@@ -11,7 +11,7 @@ services:
             - './data/logs:/opt/graphdb/logs'
         # Use 1GB of heap space
         environment:
-            GDB_HEAP_SIZE: 1gb
+            GDB_HEAP_SIZE: 1G
 
         restart: always