diff --git a/java-all-call-graph/build.gradle b/java-all-call-graph/build.gradle
index 333f555b0ca552deaa4965429ebb41f7581ae1ba..50add03e3d4f51c60de37881541bf9086d9ee1bd 100644
--- a/java-all-call-graph/build.gradle
+++ b/java-all-call-graph/build.gradle
@@ -9,8 +9,8 @@ group 'com.github.adrninistrator'
 version = "3.2.1"
 def projectName = "java-all-call-graph"
 description = "${projectName}"
-sourceCompatibility = 1.8
-targetCompatibility = 1.8
+def sourceCompatibility = 1.8
+def targetCompatibility = 1.8
 def jar_output_dir = "jar_output_dir"
 
 def defaultEncoding = 'UTF-8'
@@ -129,6 +129,11 @@ processTestResources {
     setDuplicatesStrategy(DuplicatesStrategy.INCLUDE)
 }
 
+tasks.withType(JavaCompile).configureEach {
+    sourceCompatibility = '${sourceCompatibility}'
+    targetCompatibility = '${targetCompatibility}'
+}
+
 tasks.register('createProject') {
     doFirst {
         sourceSets*.java.srcDirs*.each { it.mkdirs() }