diff --git a/src/plugins/coco/cocolanguageclient.cpp b/src/plugins/coco/cocolanguageclient.cpp
index e360b6952f6..4006a14550c 100644
--- a/src/plugins/coco/cocolanguageclient.cpp
+++ b/src/plugins/coco/cocolanguageclient.cpp
@@ -154,15 +154,11 @@ class CocoTextMark : public TextEditor::TextMark
 public:
     CocoTextMark(const FilePath &fileName, const CocoDiagnostic &diag, const Id &clientId)
         : TextEditor::TextMark(fileName, diag.range().start().line() + 1, clientId)
+        , m_severity(diag.cocoSeverity())
     {
         setLineAnnotation(diag.message());
         setToolTip(diag.message());
-        if (optional<CocoDiagnosticSeverity> severity = diag.cocoSeverity()) {
-
-            const TextEditor::TextStyle style = styleForSeverity(*severity);
-            m_annotationColor =
-                    TextEditor::TextEditorSettings::fontSettings().formatFor(style).foreground();
-        }
+        updateAnnotationColor();
     }
 
     QColor annotationColor() const override
@@ -171,6 +167,16 @@ public:
                                            : TextEditor::TextMark::annotationColor();
     }
 
+    void updateAnnotationColor()
+    {
+        if (m_severity) {
+            const TextEditor::TextStyle style = styleForSeverity(*m_severity);
+            m_annotationColor =
+                    TextEditor::TextEditorSettings::fontSettings().formatFor(style).foreground();
+        }
+    }
+
+    optional<CocoDiagnosticSeverity> m_severity;
     QColor m_annotationColor;
 };
 
@@ -180,10 +186,22 @@ public:
     CocoDiagnosticManager(Client *client)
         : DiagnosticManager(client)
     {
+        connect(TextEditor::TextEditorSettings::instance(),
+                &TextEditor::TextEditorSettings::fontSettingsChanged,
+                this,
+                &CocoDiagnosticManager::fontSettingsChanged);
         setExtraSelectionsId("CocoExtraSelections");
     }
 
 private:
+    void fontSettingsChanged(const TextEditor::FontSettings &fontSettings)
+    {
+        forAllMarks([](TextEditor::TextMark *mark){
+            static_cast<CocoTextMark *>(mark)->updateAnnotationColor();
+            mark->updateMarker();
+        });
+    }
+
     TextEditor::TextMark *createTextMark(const FilePath &filePath,
                                          const Diagnostic &diagnostic,
                                          bool /*isProjectFile*/) const override
diff --git a/src/plugins/languageclient/diagnosticmanager.cpp b/src/plugins/languageclient/diagnosticmanager.cpp
index 4ebb7f6c304..e81bda7bd8a 100644
--- a/src/plugins/languageclient/diagnosticmanager.cpp
+++ b/src/plugins/languageclient/diagnosticmanager.cpp
@@ -176,6 +176,14 @@ void DiagnosticManager::setExtraSelectionsId(const Utils::Id &extraSelectionsId)
     m_extraSelectionsId = extraSelectionsId;
 }
 
+void DiagnosticManager::forAllMarks(std::function<void (TextEditor::TextMark *)> func)
+{
+    for (const Marks &marks : qAsConst(m_marks)) {
+        for (TextEditor::TextMark *mark : marks.marks)
+            func(mark);
+    }
+}
+
 void DiagnosticManager::clearDiagnostics()
 {
     for (const DocumentUri &uri : m_diagnostics.keys())
diff --git a/src/plugins/languageclient/diagnosticmanager.h b/src/plugins/languageclient/diagnosticmanager.h
index aa229b91c00..282a5c3d065 100644
--- a/src/plugins/languageclient/diagnosticmanager.h
+++ b/src/plugins/languageclient/diagnosticmanager.h
@@ -85,6 +85,8 @@ protected:
 
     void setExtraSelectionsId(const Utils::Id &extraSelectionsId);
 
+    void forAllMarks(std::function<void (TextEditor::TextMark *)> func);
+
 private:
     struct VersionedDiagnostics
     {