diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache
index c027064edd4..0bd85e8b2da 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache
@@ -40,14 +40,8 @@ if(hasProperty('target') && target == 'android') {
             targetSdkVersion 25
         }
         compileOptions {
-            {{#java8}}
             sourceCompatibility JavaVersion.VERSION_1_8
             targetCompatibility JavaVersion.VERSION_1_8
-            {{/java8}}
-            {{^java8}}
-            sourceCompatibility JavaVersion.VERSION_1_7
-            targetCompatibility JavaVersion.VERSION_1_7
-            {{/java8}}
         }
 
         // Rename the aar correctly
@@ -92,14 +86,8 @@ if(hasProperty('target') && target == 'android') {
     apply plugin: 'java'
     apply plugin: 'maven'
 
-    {{#java8}}
     sourceCompatibility = JavaVersion.VERSION_1_8
     targetCompatibility = JavaVersion.VERSION_1_8
-    {{/java8}}
-    {{^java8}}
-    sourceCompatibility = JavaVersion.VERSION_1_7
-    targetCompatibility = JavaVersion.VERSION_1_7
-    {{/java8}}
 
     install {
         repositories.mavenInstaller {
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/build.gradle b/samples/client/petstore/java/okhttp-gson-dynamicOperations/build.gradle
index 915c36674c3..f21bac4c229 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/build.gradle
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/build.gradle
@@ -36,8 +36,8 @@ if(hasProperty('target') && target == 'android') {
             targetSdkVersion 25
         }
         compileOptions {
-            sourceCompatibility JavaVersion.VERSION_1_7
-            targetCompatibility JavaVersion.VERSION_1_7
+            sourceCompatibility JavaVersion.VERSION_1_8
+            targetCompatibility JavaVersion.VERSION_1_8
         }
 
         // Rename the aar correctly
@@ -82,8 +82,8 @@ if(hasProperty('target') && target == 'android') {
     apply plugin: 'java'
     apply plugin: 'maven'
 
-    sourceCompatibility = JavaVersion.VERSION_1_7
-    targetCompatibility = JavaVersion.VERSION_1_7
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
 
     install {
         repositories.mavenInstaller {
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/build.gradle b/samples/client/petstore/java/okhttp-gson-parcelableModel/build.gradle
index 615ed108d40..f0e701eea22 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/build.gradle
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/build.gradle
@@ -36,8 +36,8 @@ if(hasProperty('target') && target == 'android') {
             targetSdkVersion 25
         }
         compileOptions {
-            sourceCompatibility JavaVersion.VERSION_1_7
-            targetCompatibility JavaVersion.VERSION_1_7
+            sourceCompatibility JavaVersion.VERSION_1_8
+            targetCompatibility JavaVersion.VERSION_1_8
         }
 
         // Rename the aar correctly
@@ -82,8 +82,8 @@ if(hasProperty('target') && target == 'android') {
     apply plugin: 'java'
     apply plugin: 'maven'
 
-    sourceCompatibility = JavaVersion.VERSION_1_7
-    targetCompatibility = JavaVersion.VERSION_1_7
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
 
     install {
         repositories.mavenInstaller {
diff --git a/samples/client/petstore/java/okhttp-gson/build.gradle b/samples/client/petstore/java/okhttp-gson/build.gradle
index 08cb8effd2d..8db6d52554d 100644
--- a/samples/client/petstore/java/okhttp-gson/build.gradle
+++ b/samples/client/petstore/java/okhttp-gson/build.gradle
@@ -36,8 +36,8 @@ if(hasProperty('target') && target == 'android') {
             targetSdkVersion 25
         }
         compileOptions {
-            sourceCompatibility JavaVersion.VERSION_1_7
-            targetCompatibility JavaVersion.VERSION_1_7
+            sourceCompatibility JavaVersion.VERSION_1_8
+            targetCompatibility JavaVersion.VERSION_1_8
         }
 
         // Rename the aar correctly
@@ -82,8 +82,8 @@ if(hasProperty('target') && target == 'android') {
     apply plugin: 'java'
     apply plugin: 'maven'
 
-    sourceCompatibility = JavaVersion.VERSION_1_7
-    targetCompatibility = JavaVersion.VERSION_1_7
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
 
     install {
         repositories.mavenInstaller {