diff --git a/0001-Remove-usage-of-internal-sun-class-removed-in-Java-9.patch b/0001-Remove-usage-of-internal-sun-class-removed-in-Java-9.patch
new file mode 100644
index 0000000..ec9d274
--- /dev/null
+++ b/0001-Remove-usage-of-internal-sun-class-removed-in-Java-9.patch
@@ -0,0 +1,38 @@
+From 830df76092aec24f0f454f914161f87e11af270b Mon Sep 17 00:00:00 2001
+From: Mat Booth <mat.booth@gmail.com>
+Date: Tue, 30 Nov 2021 17:02:13 +0000
+Subject: [PATCH] Remove usage of internal sun class removed in Java 9
+
+---
+ .../org/kohsuke/args4j/spi/MultiPathOptionHandlerTest.java   | 5 ++---
+ 1 file changed, 2 insertions(+), 3 deletions(-)
+
+diff --git a/args4j/test/org/kohsuke/args4j/spi/MultiPathOptionHandlerTest.java b/args4j/test/org/kohsuke/args4j/spi/MultiPathOptionHandlerTest.java
+index b91f8a4..bdfee88 100644
+--- a/args4j/test/org/kohsuke/args4j/spi/MultiPathOptionHandlerTest.java
++++ b/args4j/test/org/kohsuke/args4j/spi/MultiPathOptionHandlerTest.java
+@@ -2,7 +2,6 @@ package org.kohsuke.args4j.spi;
+ 
+ import junit.framework.TestCase;
+ import org.kohsuke.args4j.CmdLineException;
+-import sun.reflect.generics.reflectiveObjects.NotImplementedException;
+ 
+ import java.lang.reflect.AnnotatedElement;
+ import java.nio.file.Path;
+@@ -100,11 +99,11 @@ public class MultiPathOptionHandlerTest extends TestCase {
+         }
+ 
+         public FieldSetter asFieldSetter() {
+-            throw new NotImplementedException();
++            throw new UnsupportedOperationException();
+         }
+ 
+         public AnnotatedElement asAnnotatedElement() {
+-            throw new NotImplementedException();
++            throw new UnsupportedOperationException();
+         }
+ 
+         List<Path> getCollection() {
+-- 
+2.33.1
+
diff --git a/args4j.spec b/args4j.spec
index 17968ea..2ef1536 100644
--- a/args4j.spec
+++ b/args4j.spec
@@ -1,6 +1,6 @@
 Name:           args4j
 Version:        2.33
-Release:        16%{?dist}
+Release:        17%{?dist}
 Summary:        Java command line arguments parser
 License:        MIT
 URL:            https://args4j.kohsuke.org
@@ -12,6 +12,9 @@ BuildRequires:  maven-local
 BuildRequires:  mvn(junit:junit)
 BuildRequires:  mvn(org.apache.felix:maven-bundle-plugin)
 
+# Fix build on Java 11/17
+Patch0: 0001-Remove-usage-of-internal-sun-class-removed-in-Java-9.patch
+
 # Stopped shipping these unused subpackages in F34
 Obsoletes: %{name}-tools < 2.33-13
 Obsoletes: %{name}-parent < 2.33-13
@@ -34,6 +37,7 @@ This package contains the API documentation for %{name}.
 
 %prep
 %setup -q -n %{name}-%{name}-site-%{version}
+%patch0 -p1
 
 # removing bundled stuff
 find -name '*.class' -exec rm -f '{}' \;
@@ -61,7 +65,7 @@ find -name '*.jar' -exec rm -f '{}' \;
 %mvn_file ":{*}" %{name}/@1 @1
 
 %build
-%mvn_build
+%mvn_build -- -Dmaven.compiler.release=11
 
 %install
 %mvn_install
@@ -73,6 +77,9 @@ find -name '*.jar' -exec rm -f '{}' \;
 %license %{name}/LICENSE.txt
 
 %changelog
+* Tue Nov 30 2021 Mat Booth <mat.booth@gmail.com> - 2.33-17
+- Fix build on Java 11/17
+
 * Mon Nov 29 2021 Mat Booth <mat.booth@gmail.com> - 2.33-16
 - Remove hard-coded source/target