diff --git a/semanticdb-kotlin/build.gradle.kts b/semanticdb-kotlin/build.gradle.kts
index 33e04b0..69be14c 100644
--- a/semanticdb-kotlin/build.gradle.kts
+++ b/semanticdb-kotlin/build.gradle.kts
@@ -15,13 +15,13 @@ buildscript {
     }
 
     dependencies {
-        classpath("com.google.protobuf:protobuf-java:3.17.3")
+        classpath("com.google.protobuf:protobuf-java:4.28.1")
     }
 }
 
 dependencies {
     implementation(kotlin("stdlib"))
-    implementation("com.google.protobuf:protobuf-java:3.17.3")
+    implementation("com.google.protobuf:protobuf-java:4.28.1")
     compileOnly("com.sourcegraph", "semanticdb-javac", "0.8.23")
 }
 
diff --git a/semanticdb-kotlinc/build.gradle.kts b/semanticdb-kotlinc/build.gradle.kts
index bae3a63..41c2c08 100644
--- a/semanticdb-kotlinc/build.gradle.kts
+++ b/semanticdb-kotlinc/build.gradle.kts
@@ -29,7 +29,7 @@ val snapshotsImplementation: Configuration by configurations.getting {
 dependencies {
     implementation(kotlin("stdlib"))
     compileOnly(kotlin("compiler-embeddable"))
-    implementation("com.google.protobuf", "protobuf-java", "3.15.7")
+    implementation("com.google.protobuf", "protobuf-java", "4.28.1")
     implementation(projects.semanticdbKotlin)
 
     testImplementation(kotlin("compiler-embeddable"))