diff --git a/core/config.mk b/core/config.mk
index eb21943..e6295d8 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -264,6 +264,10 @@
 HOST_JDK_TOOLS_JAR :=
 else
 HOST_JDK_TOOLS_JAR:= $(shell $(BUILD_SYSTEM)/find-jdk-tools-jar.sh)
+ifeq ($(wildcard $(HOST_JDK_TOOLS_JAR)),)
+$(error Error: could not find jdk tools.jar, please install JDK-5.0, \
+    update 12 or higher, which you can download from java.sun.com)
+endif
 endif
 
 # It's called md5 on Mac OS and md5sum on Linux
diff --git a/core/find-jdk-tools-jar.sh b/core/find-jdk-tools-jar.sh
index 4c40627..f21c48b 100755
--- a/core/find-jdk-tools-jar.sh
+++ b/core/find-jdk-tools-jar.sh
@@ -3,7 +3,6 @@
 else
     JAVAC=$(which javac)
     if [ -z "$JAVAC" ] ; then
-	echo "Please-install-JDK-5.0,-update-12-or-higher,-which-you-can-download-from-java.sun.com"
 	exit 1
     fi
     while [ -L $JAVAC ] ; do