diff --git a/source/RobotAPI/libraries/armem_robot/client/interfaces.h b/source/RobotAPI/libraries/armem_robot/client/interfaces.h
index 4975e53e597f54b3f451c7075e368f00f692d343..64d68ed6a3549fa7b0e6fa5745a1cc5731158a38 100644
--- a/source/RobotAPI/libraries/armem_robot/client/interfaces.h
+++ b/source/RobotAPI/libraries/armem_robot/client/interfaces.h
@@ -12,10 +12,10 @@ namespace armarx::armem::robot
     public:
         virtual ~ReaderInterface() = default;
 
-        virtual bool synchronize(Robot& obj, const armem::Time& timestamp) = 0;
+        virtual bool synchronize(Robot& obj, const armem::Time& timestamp) const = 0;
 
-        virtual Robot get(const RobotDescription& description, const armem::Time& timestamp) = 0;
-        virtual std::optional<Robot> get(const std::string& name, const armem::Time& timestamp) = 0;
+        virtual Robot get(const RobotDescription& description, const armem::Time& timestamp) const = 0;
+        virtual std::optional<Robot> get(const std::string& name, const armem::Time& timestamp) const = 0;
     };
 
     class WriterInterface