diff --git a/core/.classpath b/core/.classpath
index 453ab552f..06a9ed43d 100644
--- a/core/.classpath
+++ b/core/.classpath
@@ -17,6 +17,7 @@
 	<classpathentry kind="lib" path="lib/javax.inject.jar"/>
 	<classpathentry kind="lib" path="lib/javax.json-1.1.3.jar"/>
 	<classpathentry kind="lib" path="lib/javax.json-api-1.1.3.jar"/>
+	<classpathentry kind="lib" path="lib/javax.activation-api.2.3.1.jar"/>
 	<classpathentry kind="lib" path="lib/aopalliance.jar"/>
 	<classpathentry kind="lib" path="lib/commonmark-0.19.0.jar"/>
 	<classpathentry kind="lib" path="lib/slf4j-api-1.7.30.jar"/>
diff --git a/swing/.classpath b/swing/.classpath
index 7daea48ea..6878da13d 100644
--- a/swing/.classpath
+++ b/swing/.classpath
@@ -19,6 +19,7 @@
 	<classpathentry kind="lib" path="/OpenRocket Core/lib/javax.inject.jar"/>
 	<classpathentry kind="lib" path="/OpenRocket Core/lib/javax.json-1.1.3.jar"/>
 	<classpathentry kind="lib" path="/OpenRocket Core/lib/javax.json-api-1.1.3.jar"/>
+	<classpathentry kind="lib" path="/OpenRocket Core/lib/javax.activation-api.2.3.1.jar"/>
 	<classpathentry kind="lib" path="/OpenRocket Core/resources"/>
 	<classpathentry kind="lib" path="resources"/>
 	<classpathentry kind="lib" path="lib/miglayout-4.0-swing.jar" sourcepath="reference/miglayout-4.0-sources.jar"/>