diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache
index 1113d8b4ee..73ea697ac1 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/build.gradle.mustache
@@ -1,6 +1,9 @@
 apply plugin: 'java'
 apply plugin: 'maven'
 
+sourceCompatibility = 1.7
+targetCompatibility = 1.7
+
 repositories {
     mavenCentral()
 }
diff --git a/samples/client/petstore/java/okhttp-gson/build.gradle b/samples/client/petstore/java/okhttp-gson/build.gradle
index 96c8f7718d..53e92e5fe1 100644
--- a/samples/client/petstore/java/okhttp-gson/build.gradle
+++ b/samples/client/petstore/java/okhttp-gson/build.gradle
@@ -1,6 +1,9 @@
 apply plugin: 'java'
 apply plugin: 'maven'
 
+sourceCompatibility = 1.7
+targetCompatibility = 1.7
+
 repositories {
     mavenCentral()
 }