diff --git a/forum-network/src/classes/dao/forum.js b/forum-network/src/classes/dao/forum.js
index e311e1f..7826cca 100644
--- a/forum-network/src/classes/dao/forum.js
+++ b/forum-network/src/classes/dao/forum.js
@@ -184,6 +184,7 @@ export class Forum extends ReputationHolder {
           if (citationEdge.to.id === INCINERATOR_ADDRESS) {
             // Only a positive amount may be incinerated! Otherwise the sink could be used as a source.
             if (outboundAmount < 0) {
+              this.scene?.flowchart?.log(`style ${citationEdge.from.id} fill:#620000`);
               throw new Error('Incinerator can only receive positive citations!');
             }
             // Reputation sent to the incinerator is burned! This means it is deducted from the sender,
diff --git a/forum-network/src/tests/scripts/forum/forum8.test.js b/forum-network/src/tests/scripts/forum/forum8.test.js
index 86a7fa6..513cc91 100644
--- a/forum-network/src/tests/scripts/forum/forum8.test.js
+++ b/forum-network/src/tests/scripts/forum/forum8.test.js
@@ -34,6 +34,16 @@ describe('Forum', function tests() {
       forum.getPost(posts[0]).value.should.equal(0);
       forum.getPost(posts[1]).value.should.equal(0);
     });
+
+    it('Reputation can not be sourced from the incinerator', async () => {
+      try {
+        await forumTest.addPost(experts[0], 10, [
+          { postId: INCINERATOR_ADDRESS, weight: -1 },
+        ]);
+      } catch (e) {
+        e.message.should.match(/Incinerator can only receive positive citations/);
+      }
+    });
   });
 });