diff --git a/external/rhino/UnpackedTarball_rhino.mk b/external/rhino/UnpackedTarball_rhino.mk
index 0a1492b88da6..15a596eb1b0f 100644
--- a/external/rhino/UnpackedTarball_rhino.mk
+++ b/external/rhino/UnpackedTarball_rhino.mk
@@ -17,6 +17,7 @@ $(eval $(call gb_UnpackedTarball_add_patches,rhino,\
 	external/rhino/rhino1_5R5.patch \
 	external/rhino/rhino1_5R5-find_swing.patch \
 	external/rhino/rhino1_5R5-updateToolTip.patch \
+	external/rhino/rhino-classpath.patch.1 \
 ))
 
 $(eval $(call gb_UnpackedTarball_add_file,rhino,toolsrc/org/mozilla/javascript/tools/debugger/OfficeScriptInfo.java,external/rhino/OfficeScriptInfo.java))
diff --git a/external/rhino/rhino-classpath.patch.1 b/external/rhino/rhino-classpath.patch.1
new file mode 100644
index 000000000000..c751b95b5d9b
--- /dev/null
+++ b/external/rhino/rhino-classpath.patch.1
@@ -0,0 +1,13 @@
+/usr/bin/ant will put dozens of jars on the classpath, including a
+rhino.jar that breaks the build
+
+--- rhino/build.xml.orig	2021-11-11 17:25:07.284267174 +0100
++++ rhino/build.xml	2021-11-11 17:25:38.689242510 +0100
+@@ -33,6 +33,7 @@
+     <property file="apiClasses.properties"/>
+     <property name="docsrc.dir" value="docs"/>
+     <property name="dist.docsrc.dir" value="src/docs"/>
++    <property name="build.sysclasspath" value="ignore"/>
+   </target>
+ 
+   <target name="init" depends="properties">