diff --git a/compiler-plugin/src/test/kotlin/com/google/devtools/ksp/test/AbstractKSPTest.kt b/compiler-plugin/src/test/kotlin/com/google/devtools/ksp/test/AbstractKSPTest.kt
index 78a3fff699..826f5eff8c 100644
--- a/compiler-plugin/src/test/kotlin/com/google/devtools/ksp/test/AbstractKSPTest.kt
+++ b/compiler-plugin/src/test/kotlin/com/google/devtools/ksp/test/AbstractKSPTest.kt
@@ -185,7 +185,7 @@ abstract class AbstractKSPTest(frontend: FrontendKind<*>) : DisposableTest() {
             "-classpath", classpath,
             "-d", module.outDir.path
         )
-        compileJavaFiles(javaFiles, options)
+        compileJavaFiles(javaFiles, options, assertions = JUnit5Assertions)
     }
 
     fun runTest(@TestDataFile path: String) {
diff --git a/gradle.properties b/gradle.properties
index 2e2936e9ea..36f155f1ae 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,7 +1,7 @@
 # Copied from kotlinc
 org.gradle.jvmargs=-Duser.country=US -Dkotlin.daemon.jvm.options=-Xmx4096m -Dfile.encoding=UTF-8
 
-kotlinBaseVersion=2.1.20-dev-3305
+kotlinBaseVersion=2.1.0
 agpBaseVersion=7.3.1
 agpTestVersion=8.7.1
 intellijVersion=233.13135.128
@@ -26,4 +26,4 @@ kotlin.jvm.target.validation.mode=warning
 
 # Build or runtime dependencies of this project
 buildKotlinVersion=2.0.20
-buildKspVersion=2.0.20-1.0.25
\ No newline at end of file
+buildKspVersion=2.0.20-1.0.25