diff --git a/docs/book/10-Interfaces.md b/docs/book/10-Interfaces.md
index 7625e07b..493fb91f 100644
--- a/docs/book/10-Interfaces.md
+++ b/docs/book/10-Interfaces.md
@@ -73,8 +73,8 @@ abstract class Basic3 {
 }
 
 public class AbstractWithoutAbstracts {
-    // Basic b3 = new Basic3();
-    // error: Basic 3 is abstract; cannot be instantiated
+    // Basic3 b3 = new Basic3();
+    // error: Basic3 is abstract; cannot be instantiated
 }
 ```