--- a/build.gradle
+++ b/build.gradle
@@ -742,9 +742,9 @@
     if (inStream.readLine() != null) {
         String v = inStream.readLine();
         if (v != null) {
-            int ib = v.indexOf(" (build ");
+            int ib = v.indexOf(" (guix build ");
             if (ib != -1) {
-                String ver = v.substring(ib + 8, v.size() - 1);
+                String ver = v.substring(ib + 13, v.size() - 1);
 
                 defineProperty("jdkRuntimeVersion", ver)
                 defineProperty("jdkVersion", jdkRuntimeVersion.split("-")[0])