diff --git a/build.sh b/build.sh
index 4c218990..a8f98aa3 100755
--- a/build.sh
+++ b/build.sh
@@ -2,6 +2,8 @@
 
 set -e
 
+export JAVA_HOME=${JAVA_HOME:-`asdf where java`}
+
 ant generate-all
 
 ant compile