diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 4e88342..fc5090b 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ ubuntu-latest, macOS-latest ]
+        os: [ ubuntu-latest, macOS-latest, windows-latest ]
     steps:
       - uses: actions/checkout@v3
       - name: Set up JDK 11
diff --git a/pprint-kotlin-core/build.gradle.kts b/pprint-kotlin-core/build.gradle.kts
index 5b99737..e81c0f5 100644
--- a/pprint-kotlin-core/build.gradle.kts
+++ b/pprint-kotlin-core/build.gradle.kts
@@ -14,7 +14,7 @@ plugins {
 
 kotlin {
   jvm {
-    jvmToolchain(8)
+    jvmToolchain(11)
   }
 
   linuxX64()
diff --git a/pprint-kotlin-kmp/build.gradle.kts b/pprint-kotlin-kmp/build.gradle.kts
index 84e6b3f..609a8e5 100644
--- a/pprint-kotlin-kmp/build.gradle.kts
+++ b/pprint-kotlin-kmp/build.gradle.kts
@@ -13,7 +13,7 @@ plugins {
 
 kotlin {
   jvm {
-    jvmToolchain(8)
+    jvmToolchain(11)
   }
 
   linuxX64()
diff --git a/pprint-kotlin/build.gradle.kts b/pprint-kotlin/build.gradle.kts
index ec7b445..5b7379f 100644
--- a/pprint-kotlin/build.gradle.kts
+++ b/pprint-kotlin/build.gradle.kts
@@ -11,7 +11,7 @@ tasks.named<Test>("test") {
 }
 
 kotlin {
-  jvmToolchain(8)
+  jvmToolchain(11)
 }
 
 dependencies {