diff --git a/Dockerfile b/Dockerfile
index 455e64f8..cae143f7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -37,10 +37,10 @@ ARG NOVA_TSS_USER=tss
 ARG NOVA_TSS_UID=42434
 ARG NOVA_TSS_GID=42434
 
-ARG NOVNC_REPO=${NOVNC_REPO:-https://github.com/novnc/novnc}
-ARG NOVNC_REF=${NOVNC_REF:-v1.0.0}
-ARG SPICE_REPO=${SPICE_REPO:-https://gitlab.freedesktop.org/spice/spice-html5.git}
-ARG SPICE_REF=${SPICE_REF:-spice-html5-0.1.6}
+ARG NOVNC_REPO=https://github.com/novnc/novnc
+ARG NOVNC_REF=v1.0.0
+ARG SPICE_REPO=https://gitlab.freedesktop.org/spice/spice-html5.git
+ARG SPICE_REF=spice-html5-0.1.6
 
 # End Nova arguments