diff --git a/build-conventions/build.gradle.kts b/build-conventions/build.gradle.kts
index 86f30440..fe1616d0 100644
--- a/build-conventions/build.gradle.kts
+++ b/build-conventions/build.gradle.kts
@@ -4,6 +4,14 @@ plugins {
     `kotlin-dsl`
 }
 
+// Per conversation in the KotlinLang Slack, Gradle uses Java 8 compatibility internally
+// for all build scripts.
+// https://kotlinlang.slack.com/archives/C19FD9681/p1636632870122900?thread_ts=1636572288.117000&cid=C19FD9681
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
 dependencies {
     val rootProperties = getRootProperties()
 
diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
index f6120a7f..9c9aaa31 100644
--- a/buildSrc/build.gradle.kts
+++ b/buildSrc/build.gradle.kts
@@ -4,6 +4,14 @@ plugins {
     `kotlin-dsl-base`
 }
 
+// Per conversation in the KotlinLang Slack, Gradle uses Java 8 compatibility internally
+// for all build scripts.
+// https://kotlinlang.slack.com/archives/C19FD9681/p1636632870122900?thread_ts=1636572288.117000&cid=C19FD9681
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
 repositories {
     mavenCentral()
 }