diff --git a/core/c/jbigi/build.sh b/core/c/jbigi/build.sh
index c41a2ee7a6e2d6f925281554460eedb57180153d..6c662cba453476cf3426c9024adccb23dd249b24 100755
--- a/core/c/jbigi/build.sh
+++ b/core/c/jbigi/build.sh
@@ -25,7 +25,7 @@ mkdir -p lib bin/local
 
 
 # If JAVA_HOME isn't set, try to figure it out on our own
-[ -z $JAVA_HOME ] && . ../find-java-home
+[ -z "$JAVA_HOME" ] && . ../find-java-home
 if [ ! -f "$JAVA_HOME/include/jni.h" ]; then
     echo "ERROR: Cannot find jni.h! Looked in \"$JAVA_HOME/include/jni.h\"" >&2
     echo "Please set JAVA_HOME to a java home that has the JNI" >&2