diff --git a/prepare/compiler/compiler.pro b/prepare/compiler/compiler.pro
index 2b512e30aec..604e5b45d94 100644
--- a/prepare/compiler/compiler.pro
+++ b/prepare/compiler/compiler.pro
@@ -285,3 +285,6 @@
     public ** plus(java.lang.Object, java.lang.Object);
     public ** plusAll(java.util.Map);
 }
+
+# This class is needed for test framework
+-keep class com.intellij.openapi.util.text.StringUtil { *; }