diff --git a/drydocker/docker/build.sh b/drydocker/docker/build.sh
index 365b8e7..e4956a5 100755
--- a/drydocker/docker/build.sh
+++ b/drydocker/docker/build.sh
@@ -1,25 +1,33 @@
 #!/bin/bash
 
 # Require free disk space (>= 30%)
 df=$(sudo df /var/lib/docker 2>/dev/null | tail -n 1 | awk '{print $4/$2}')
 
 if [ -z "${df}" ]; then
     echo "Undetermined amount of free space, cleaning up in any case."
     make clean
 elif [ $( bc <<< "${df} <= 0.30" ) == 1 ]; then
     make clean
 
     df=$(sudo df /var/lib/docker 2>/dev/null | tail -n 1 | awk '{print $4/$2}')
     if [ $( bc <<< "$df <= 0.30" ) == 1 ]; then
         echo "Cannot get disk space consumption to under 70%"
         exit 1
     fi
 fi
 
+pushd /srv/${PACKAGE}.git
+num_behind=$(git format-patch ${COMMIT}..master | wc -l)
+if [ ${num_behind} -gt 0 ]; then
+    echo "SKIPPED: make (behind master)"
+    exit 0
+fi
+popd
+
 make all; retval=$?
 
 for image in $(docker images -aq --filter=dangling=true); do
     docker rmi $image || :
 done
 
 exit ${retval}