1 files changed, 3 insertions, 2 deletions
diff --git a/src/dabInputZmq.h b/src/dabInputZmq.h
index cb7fdd4..5c88316 100644
--- a/src/dabInputZmq.h
+++ b/src/dabInputZmq.h
@@ -90,10 +90,11 @@ class DabInputZmqBase : public DabInputBase, public RemoteControllable {
         virtual int close();
 
         /* Remote control */
-        virtual void set_parameter(string parameter, string value);
+        virtual void set_parameter(const string& parameter,
+               const string& value);
 
         /* Getting a parameter always returns a string. */
-        virtual string get_parameter(string parameter);
+        virtual const string get_parameter(const string& parameter) const;
 
     protected:
         virtual int readFromSocket(int framesize) = 0;