diff --git a/javaoverlay-plugin/src/main/groovy/com/dim/javaoverlay/task/process/SourceProcessor.groovy b/javaoverlay-plugin/src/main/groovy/com/dim/javaoverlay/task/process/SourceProcessor.groovy
index bf01c0f..3432d72 100644
--- a/javaoverlay-plugin/src/main/groovy/com/dim/javaoverlay/task/process/SourceProcessor.groovy
+++ b/javaoverlay-plugin/src/main/groovy/com/dim/javaoverlay/task/process/SourceProcessor.groovy
@@ -26,7 +26,9 @@ public class SourceProcessor implements IProcessor {
         if (!classMapFile.getParentFile().exists()) {
             classMapFile.getParentFile().mkdirs();
         } else {
-            getLocalClassMap();
+            if (classMapFile.exists()) {
+                getLocalClassMap();
+            }
         }
     }