diff --git a/ethereumj-core/build.gradle b/ethereumj-core/build.gradle
index d3479f19..22ab6fc4 100644
--- a/ethereumj-core/build.gradle
+++ b/ethereumj-core/build.gradle
@@ -37,6 +37,7 @@ antlr4 {
 compileJava.dependsOn antlr4
 
 test {
+    systemProperty "file.encoding", "UTF-8"
     jvmArgs '-Xss16m'
 }