diff --git a/pom.xml b/pom.xml
index 91dae65..ea94847 100644
--- a/pom.xml
+++ b/pom.xml
@@ -26,7 +26,7 @@
         <dependency>
             <groupId>com.google.protobuf</groupId>
             <artifactId>protobuf-java</artifactId>
-            <version>2.6.1</version>
+            <version>3.16.3</version>
         </dependency>
         <dependency>
             <groupId>com.conveyal</groupId>