diff --git a/build.sh b/build.sh
index 6a74434..a1a6666 100755
--- a/build.sh
+++ b/build.sh
@@ -35,7 +35,7 @@ docker tag  $IMAGE:$STAMP $IMAGE:$ALIAS
 docker push $IMAGE:$ALIAS
 docker tag  $IMAGE:$ALIAS $IMAGE:$SUITE
 docker push $IMAGE:$SUITE
-if $SUITE = stable; then
+if test $SUITE = stable; then
     docker tag  $IMAGE:$SUITE $IMAGE
     docker push $IMAGE
 fi
diff --git a/derive.sh b/derive.sh
index ae8ff68..f9545f0 100755
--- a/derive.sh
+++ b/derive.sh
@@ -22,7 +22,7 @@ docker tag  $IMAGE:$STAMP $IMAGE:$ALIAS
 docker push $IMAGE:$ALIAS
 docker tag  $IMAGE:$ALIAS $IMAGE:$SUITE
 docker push $IMAGE:$SUITE
-if $SUITE = stable; then
+if test $SUITE = stable; then
     docker tag  $IMAGE:$SUITE $IMAGE
     docker push $IMAGE
 fi