diff --git a/cstore/datapackstore.h b/cstore/datapackstore.h
--- a/cstore/datapackstore.h
+++ b/cstore/datapackstore.h
@@ -31,7 +31,7 @@
     std::vector<delta_chain_t> _chains;
     DeltaChainIterator() :
       _index(0) {}
-    virtual delta_chain_t getNextChain(const Key &key) {
+    virtual delta_chain_t getNextChain(const Key& /*key*/) {
       return COMPOUND_LITERAL(delta_chain_t) { GET_DELTA_CHAIN_NOT_FOUND };
     }
   public:
@@ -99,7 +99,7 @@
       _store(store),
       _missing(missing) {}
 
-    Key *next();
+    Key *next() override;
 };
 
 /* Manages access to a directory of datapack files. */
diff --git a/cstore/match.h b/cstore/match.h
--- a/cstore/match.h
+++ b/cstore/match.h
@@ -21,10 +21,16 @@
 class AlwaysMatcher : public Matcher {
   public:
     AlwaysMatcher() {}
-    virtual ~AlwaysMatcher() {}
-    virtual bool matches(const std::string &path) { return true; }
-    virtual bool matches(const char *path, const size_t pathlen) { return true; }
-    virtual bool visitdir(const std::string &path) { return true; }
+    ~AlwaysMatcher() override {}
+    bool matches(const std::string& /*path*/) override {
+      return true;
+    }
+    bool matches(const char* /*path*/, const size_t /*pathlen*/) override {
+      return true;
+    }
+    bool visitdir(const std::string& /*path*/) override {
+      return true;
+    }
 };
 
 #endif // FBHGEXT_CSTORE_MATCH_H
diff --git a/cstore/uniondatapackstore.h b/cstore/uniondatapackstore.h
--- a/cstore/uniondatapackstore.h
+++ b/cstore/uniondatapackstore.h
@@ -33,14 +33,15 @@
       _store(store),
       _missing(missing) {}
 
-    Key *next();
+    Key *next() override;
 };
 
 class UnionDeltaChainIterator: public DeltaChainIterator {
   private:
     UnionDatapackStore &_store;
   protected:
-    delta_chain_t getNextChain(const Key &key);
+    delta_chain_t getNextChain(const Key &key) override;
+
   public:
     UnionDeltaChainIterator(UnionDatapackStore &store, const Key &key) :
       DeltaChainIterator(),
@@ -55,9 +56,9 @@
 
     UnionDatapackStore(std::vector<DatapackStore*> stores);
 
-    ~UnionDatapackStore();
+    ~UnionDatapackStore() override;
 
-    ConstantStringRef get(const Key &key);
+    ConstantStringRef get(const Key &key) override;
 
     UnionDeltaChainIterator getDeltaChain(const Key &key);
 
diff --git a/ctreemanifest/treemanifest.cpp b/ctreemanifest/treemanifest.cpp
--- a/ctreemanifest/treemanifest.cpp
+++ b/ctreemanifest/treemanifest.cpp
@@ -301,10 +301,11 @@
 };
 
 static FindResult get_callback(
-    Manifest *manifest,
-    const char *filename, size_t filenamelen,
-    FindContext *context,
-    ManifestPtr *resultManifest) {
+    Manifest* manifest,
+    const char* filename,
+    size_t filenamelen,
+    FindContext* context,
+    ManifestPtr* /*resultManifest*/) {
   GetResult *result = (GetResult *) context->extras;
 
   // position the iterator at the right location