diff --git a/spark-2.1.1/external/kinesis-asl-assembly/pom.xml b/spark-2.1.1/external/kinesis-asl-assembly/pom.xml
index e3305e9..1c65910 100644
--- a/spark-2.1.1/external/kinesis-asl-assembly/pom.xml
+++ b/spark-2.1.1/external/kinesis-asl-assembly/pom.xml
@@ -62,11 +62,11 @@
     <dependency>
       <groupId>com.google.protobuf</groupId>
       <artifactId>protobuf-java</artifactId>
-      <version>2.6.1</version>
+      <version>3.16.3</version>
       <!-- 
          We are being explicit about version here and overriding the 
          spark default of 2.5.0 because KCL appears to have introduced 
-         a dependency on protobuf 2.6.1 somewhere between KCL 1.4.0 and 1.6.1.
+         a dependency on protobuf 3.16.3 somewhere between KCL 1.4.0 and 1.6.1.
        -->
     </dependency>
     <dependency>
diff --git a/spark-2.1.1/pom.xml b/spark-2.1.1/pom.xml
index a985cf0..7751841 100644
--- a/spark-2.1.1/pom.xml
+++ b/spark-2.1.1/pom.xml
@@ -123,7 +123,7 @@
     <slf4j.version>1.7.16</slf4j.version>
     <log4j.version>1.2.17</log4j.version>
     <hadoop.version>2.2.0</hadoop.version>
-    <protobuf.version>2.5.0</protobuf.version>
+    <protobuf.version>3.16.3</protobuf.version>
     <yarn.version>${hadoop.version}</yarn.version>
     <flume.version>1.6.0</flume.version>
     <zookeeper.version>3.4.5</zookeeper.version>