diff --git a/tomcat-cas/bin/tool-wrapper.bat b/tomcat-cas/bin/tool-wrapper.bat
index fcff6da..331d42e 100644
--- a/tomcat-cas/bin/tool-wrapper.bat
+++ b/tomcat-cas/bin/tool-wrapper.bat
@@ -36,6 +36,7 @@
 rem                   containing some jars in order to allow replacement of APIs
 rem                   created outside of the JCP (i.e. DOM and SAX from W3C).
 rem                   It can also be used to update the XML parser implementation.
+rem                   Note that Java 9 no longer supports this feature.
 rem                   Defaults to $CATALINA_HOME/endorsed.
 rem ---------------------------------------------------------------------------
 
@@ -82,6 +83,19 @@
 
 set JAVA_OPTS=%JAVA_OPTS% -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager
 
+rem Java 9 no longer supports the java.endorsed.dirs
+rem system property. Only try to use it if
+rem JAVA_ENDORSED_DIRS was explicitly set
+rem or CATALINA_HOME/endorsed exists.
+set ENDORSED_PROP=ignore.endorsed.dirs
+if "%JAVA_ENDORSED_DIRS%" == "" goto noEndorsedVar
+set ENDORSED_PROP=java.endorsed.dirs
+goto doneEndorsed
+:noEndorsedVar
+if not exist "%CATALINA_HOME%\endorsed" goto doneEndorsed
+set ENDORSED_PROP=java.endorsed.dirs
+:doneEndorsed
+
 rem Get remaining unshifted command line arguments and save them in the
 set CMD_LINE_ARGS=
 :setArgs
@@ -91,6 +105,6 @@
 goto setArgs
 :doneSetArgs
 
-%_RUNJAVA% %JAVA_OPTS% %TOOL_OPTS% -Djava.endorsed.dirs="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Dcatalina.home="%CATALINA_HOME%" org.apache.catalina.startup.Tool %CMD_LINE_ARGS%
+%_RUNJAVA% %JAVA_OPTS% %TOOL_OPTS% -D%ENDORSED_PROP%="%JAVA_ENDORSED_DIRS%" -classpath "%CLASSPATH%" -Dcatalina.home="%CATALINA_HOME%" org.apache.catalina.startup.Tool %CMD_LINE_ARGS%
 
 :end