diff --git a/.github/workflows/build-master.yml b/.github/workflows/build-master.yml
index 1f90d358..2cb6235e 100644
--- a/.github/workflows/build-master.yml
+++ b/.github/workflows/build-master.yml
@@ -12,10 +12,10 @@ jobs:
       - name: Checkout latest code
         uses: actions/checkout@v3
 
-      - name: Set up JDK 11
+      - name: Set up JDK 17
         uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: 17
           distribution: 'zulu'
           cache: 'gradle'
 
diff --git a/.github/workflows/dokka.yml b/.github/workflows/dokka.yml
index 666d3a94..ce75f5c3 100644
--- a/.github/workflows/dokka.yml
+++ b/.github/workflows/dokka.yml
@@ -14,10 +14,10 @@ jobs:
       - name: Checkout latest code
         uses: actions/checkout@v3
 
-      - name: Set up JDK 11
+      - name: Set up JDK 17
         uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: 17
           distribution: 'zulu'
           cache: 'gradle'
 
diff --git a/.github/workflows/manual_testing.yml b/.github/workflows/manual_testing.yml
index 12f595f7..aa1f1bf2 100644
--- a/.github/workflows/manual_testing.yml
+++ b/.github/workflows/manual_testing.yml
@@ -15,10 +15,10 @@ jobs:
         with:
           ref: add-arm64-architecture
 
-      - name: Set up JDK 11
+      - name: Set up JDK 17
         uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: 17
           distribution: 'zulu'
           cache: 'gradle'
 
diff --git a/.github/workflows/publish-release.yml b/.github/workflows/publish-release.yml
index 59f40801..2cb90446 100644
--- a/.github/workflows/publish-release.yml
+++ b/.github/workflows/publish-release.yml
@@ -15,10 +15,10 @@ jobs:
       - name: Checkout latest code
         uses: actions/checkout@v3
 
-      - name: Set up JDK 11
+      - name: Set up JDK 17
         uses: actions/setup-java@v3
         with:
-          java-version: 11
+          java-version: 17
           distribution: 'zulu'
           cache: 'gradle'
 
diff --git a/build.gradle.kts b/build.gradle.kts
index a04103eb..18f9e787 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -41,8 +41,8 @@ application {
 }
 
 java {
-    sourceCompatibility = JavaVersion.VERSION_11
-    targetCompatibility = JavaVersion.VERSION_11
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
     withJavadocJar()
     withSourcesJar()
 }
@@ -187,7 +187,7 @@ jib {
                 os = "linux"
             }
         }
-        image = "gcr.io/distroless/java11-debian11"
+        image = "gcr.io/distroless/java17-debian11"
     }
     container {
         ports = listOf("8080")
@@ -254,7 +254,7 @@ tasks {
 
     withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
         kotlinOptions {
-            jvmTarget = JavaVersion.VERSION_11.toString()
+            jvmTarget = JavaVersion.VERSION_17.toString()
         }
     }
 
diff --git a/src/main/kotlin/no/nav/security/mock/oauth2/http/OAuth2HttpRequestHandler.kt b/src/main/kotlin/no/nav/security/mock/oauth2/http/OAuth2HttpRequestHandler.kt
index bcac1bb2..124c7610 100644
--- a/src/main/kotlin/no/nav/security/mock/oauth2/http/OAuth2HttpRequestHandler.kt
+++ b/src/main/kotlin/no/nav/security/mock/oauth2/http/OAuth2HttpRequestHandler.kt
@@ -22,7 +22,6 @@ import no.nav.security.mock.oauth2.extensions.OAuth2Endpoints.OAUTH2_WELL_KNOWN
 import no.nav.security.mock.oauth2.extensions.OAuth2Endpoints.OIDC_WELL_KNOWN
 import no.nav.security.mock.oauth2.extensions.OAuth2Endpoints.REVOKE
 import no.nav.security.mock.oauth2.extensions.OAuth2Endpoints.TOKEN
-import no.nav.security.mock.oauth2.extensions.clientAuthentication
 import no.nav.security.mock.oauth2.extensions.isPrompt
 import no.nav.security.mock.oauth2.extensions.issuerId
 import no.nav.security.mock.oauth2.extensions.toIssuerUrl