diff --git a/Earthfile b/Earthfile
index 79db3bb..c6a81c8 100644
--- a/Earthfile
+++ b/Earthfile
@@ -35,6 +35,7 @@ docker:
     rm -v audiowaveform_1.8.1-1-12_amd64.deb && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*
+  ARG tag=trunk
   SAVE IMAGE --push upend/upend:$tag
 
 upend-bin: