diff --git a/data/syntax/rmarkdown.xml b/data/syntax/rmarkdown.xml
--- a/data/syntax/rmarkdown.xml
+++ b/data/syntax/rmarkdown.xml
@@ -15,7 +15,7 @@
 section="Markup"
 extensions="*.rmd;*.Rmd;*.RMD"
 mimetype="text/x-r-markdown"
-version="3"
+version="4"
 kateversion="3.4"
 casesensitive="true"
 author="Dirk Sarpe (dsarpe@posteo.de)"
@@ -73,6 +73,7 @@
       <itemData name="Markdown" defStyleNum="dsNormal"/>
       <itemData name="Structure" defStyleNum="dsRegionMarker"/>
       <itemData name="MathMode" defStyleNum="dsRegionMarker" color="#00A000"/>
+      <itemData name="Document Headers" defStyleNum="dsOthers"/>
     </itemDatas>
 
   </highlighting>
diff --git a/src/indexer/katehighlightingindexer.cpp b/src/indexer/katehighlightingindexer.cpp
--- a/src/indexer/katehighlightingindexer.cpp
+++ b/src/indexer/katehighlightingindexer.cpp
@@ -174,18 +174,19 @@
 
     bool check() const
     {
+        bool success = true;
         const auto invalidNames = m_usedNames - m_existingNames;
         if (!invalidNames.isEmpty()) {
             qWarning() << m_filename << "Reference of non-existing keyword list:" << invalidNames;
-            return false;
+            success = false;
         }
 
         const auto unusedNames = m_existingNames - m_usedNames;
         if (!unusedNames.isEmpty()) {
             qWarning() << m_filename << "Unused keyword lists:" << unusedNames;
         }
 
-        return true;
+        return success;
     }
 
 private:
@@ -488,7 +489,7 @@
 
             // check single chars in DetectChar and Detect2Chars
             if (!checkSingleChars(hlFilename, xml)) {
-//                 anyError = 8;
+                anyError = 8;
                 continue;
             }
 
@@ -500,11 +501,11 @@
         }
 
         if (!attributeChecker.check()) {
-            //anyError = 7;
+            anyError = 7;
         }
 
         if (!keywordChecker.check()) {
-            //anyError = 7;
+            anyError = 7;
         }
     }