diff --git a/docker/debian-7-64bit/run.sh b/docker/debian-7-64bit/run.sh
index a2c6e91..06c509c 100755
--- a/docker/debian-7-64bit/run.sh
+++ b/docker/debian-7-64bit/run.sh
@@ -17,6 +17,9 @@ export NATIVE_PLATFORM=debian
 if [ -z "$PLATFORM" ]; then
     export PLATFORM=linux
 fi
+if [ -z "$ARCH" ]; then
+    export ARCH=64
+fi
 if [ -z "$TASK" ]; then
     export TASK=builder-$NATIVE_PLATFORM
 fi