diff --git a/build.gradle b/build.gradle
index e307171..4783a91 100644
--- a/build.gradle
+++ b/build.gradle
@@ -358,7 +358,7 @@ dependencies {
 	testImplementation('joda-time:joda-time:2.2')
 	// needed for syslog4j. Used in java test modules and JsonServerServlet subclasses in tests
 	// but not in SDK code proper.
-	testImplementation('net.java.dev.jna:jna:3.4.0')
+	testImplementation('net.java.dev.jna:jna:5.18.1')
 	testImplementation("nl.jqno.equalsverifier:equalsverifier:4.0.7")
 	// this is OOOOOOLD. But that probably means updating java_common
 	testImplementation('org.eclipse.jetty.aggregate:jetty-all:7.0.0.v20091005')
@@ -387,7 +387,7 @@ dependencies {
 	generatedCodeClasspath('javax.servlet:servlet-api:2.5')
 	generatedCodeClasspath('joda-time:joda-time:2.2')
 	generatedCodeClasspath('junit:junit:4.12')
-	generatedCodeClasspath('net.java.dev.jna:jna:3.4.0')
+	generatedCodeClasspath('net.java.dev.jna:jna:5.18.1')
 	generatedCodeClasspath('org.eclipse.jetty.aggregate:jetty-all:7.0.0.v20091005')
 	generatedCodeClasspath('org.hamcrest:hamcrest-core:1.3')
 	generatedCodeClasspath('org.ini4j:ini4j:0.5.2')