diff --git a/sigstore-java/build.gradle.kts b/sigstore-java/build.gradle.kts
index 97049be5..e8b7bdbf 100644
--- a/sigstore-java/build.gradle.kts
+++ b/sigstore-java/build.gradle.kts
@@ -5,7 +5,7 @@ plugins {
     id("build-logic.test-junit5")
     id("build-logic.build-info")
     id("org.jsonschema2dataclass") version "5.0.0"
-    id("com.google.protobuf") version "0.9.5"
+    id("com.google.protobuf") version "0.9.6"
 }
 
 description = "A Java client for signing and verifying using Sigstore"
@@ -24,11 +24,11 @@ dependencies {
     // this requires inclusion of protos is src/main/proto
     protobuf("dev.sigstore:protobuf-specs:0.5.0")
 
-    implementation(platform("com.google.protobuf:protobuf-bom:4.30.2"))
+    implementation(platform("com.google.protobuf:protobuf-bom:4.33.2"))
     implementation("com.google.protobuf:protobuf-java-util")
 
     // grpc deps
-    implementation(platform("io.grpc:grpc-bom:1.71.0"))
+    implementation(platform("io.grpc:grpc-bom:1.78.0"))
     implementation("io.grpc:grpc-protobuf")
     implementation("io.grpc:grpc-stub")
     runtimeOnly("io.grpc:grpc-netty-shaded")
@@ -61,11 +61,11 @@ dependencies {
 
 protobuf {
     protoc {
-        artifact = "com.google.protobuf:protoc:4.30.2"
+        artifact = "com.google.protobuf:protoc:4.33.2"
     }
     plugins {
         id("grpc") {
-            artifact = "io.grpc:protoc-gen-grpc-java:1.71.0"
+            artifact = "io.grpc:protoc-gen-grpc-java:1.78.0"
         }
     }
     generateProtoTasks {