diff --git a/docs/callgraphs.md b/docs/callgraphs.md
index 4103da9fdfc..65ace2dde82 100644
--- a/docs/callgraphs.md
+++ b/docs/callgraphs.md
@@ -184,10 +184,10 @@ You can construct a call graph with Qilin as follows:
 
 ==="SootUp"
 
-```java
-String MAINCLASS = "dacapo.antlr.Main"; // just an example
-PTAPattern ptaPattern = new PTAPattern("insens"); // "2o"=>2OBJ, "1c"=>1CFA, etc.
-PTA pta = PTAFactory.createPTA(ptaPattern, view, MAINCLASS);
-pta.run();
-CallGraph cg = pta.getCallGraph();
-```
\ No newline at end of file
+    ```java
+    String MAINCLASS = "dacapo.antlr.Main"; // just an example
+    PTAPattern ptaPattern = new PTAPattern("insens"); // "2o"=>2OBJ, "1c"=>1CFA, etc.
+    PTA pta = PTAFactory.createPTA(ptaPattern, view, MAINCLASS);
+    pta.run();
+    CallGraph cg = pta.getCallGraph();
+    ```
\ No newline at end of file