diff --git a/src/main/java/com/rultor/agents/github/qtn/QnMerge.java b/src/main/java/com/rultor/agents/github/qtn/QnMerge.java
index 5a585c7c04..85c22e265e 100644
--- a/src/main/java/com/rultor/agents/github/qtn/QnMerge.java
+++ b/src/main/java/com/rultor/agents/github/qtn/QnMerge.java
@@ -77,25 +77,30 @@ public Req understand(final Comment.Smart comment,
                 issue.repo().coordinates(), issue.number(), comment.number()
             );
             final CheckablePull pull = new CheckablePull(issue.pull());
-            if (pull.containsFile(".rultor.yml")) {
+            final String sysfile = ".rultor.yml";
+            if (pull.containsFile(sysfile)) {
                 new Answer(comment).post(
-                        false,
-                        QnMerge.PHRASES
-                                .getString("QnMerge.system-files-affected")
+                    false,
+                    String.format(
+                        QnMerge.PHRASES.getString(
+                            "QnMerge.system-files-affected"
+                        ),
+                        sysfile
+                    )
                 );
                 req = Req.DONE;
             } else
                 if (pull.allChecksSuccessful()) {
                     new Answer(comment).post(
-                            true,
-                            String.format(
-                                    QnMerge.PHRASES.getString("QnMerge.start"),
-                                    home.toASCIIString()
-                            )
+                        true,
+                        String.format(
+                                QnMerge.PHRASES.getString("QnMerge.start"),
+                                home.toASCIIString()
+                        )
                     );
                     req = QnMerge.pack(
-                            comment,
-                            issue.repo().pulls().get(issue.number())
+                        comment,
+                        issue.repo().pulls().get(issue.number())
                     );
                 } else {
                     new Answer(comment).post(
diff --git a/src/main/resources/phrases_en_US.properties b/src/main/resources/phrases_en_US.properties
index 5d2589e721..2578b4a206 100644
--- a/src/main/resources/phrases_en_US.properties
+++ b/src/main/resources/phrases_en_US.properties
@@ -36,8 +36,11 @@ QnMerge.checks-are-failed=Can't merge it. Some CI checks were failed. \
                           Apparently, the pull request is not ready to be \
                           merged since it has some problems. \
                           Please, fix them first.
-QnMerge.system-files-affected=Can't merge it. File `.rultor.yml` is affected by \
-                              this pull request.
+QnMerge.system-files-affected=Can't merge this pull requests, because the file \
+                              `%s` was modified. This is a security threat. \
+                              Make a separate pull request with the \
+                              modification of this particular file and ask \
+                              project architect to merge it manually.
 
 QnDeploy.start=OK, I'll try to deploy now. You can check the progress [here](%s)
 
diff --git a/src/test/java/com/rultor/agents/github/qtn/QnMergeTest.java b/src/test/java/com/rultor/agents/github/qtn/QnMergeTest.java
index 88787c3edb..1d0729025f 100644
--- a/src/test/java/com/rultor/agents/github/qtn/QnMergeTest.java
+++ b/src/test/java/com/rultor/agents/github/qtn/QnMergeTest.java
@@ -226,9 +226,9 @@ public void stopsBecauseSystemFilesAffected()
         MatcherAssert.assertThat(
                 new Comment.Smart(this.comments.get(2)).body(),
                 Matchers.containsString(
-                        QnMergeTest.PHRASES.getString(
-                            "QnMerge.system-files-affected"
-                        )
+                    QnMergeTest.PHRASES.getString(
+                        "QnMerge.system-files-affected"
+                    )
                 )
         );
     }