diff --git a/Makefile b/Makefile
index 3cc63bf..23a8b6a 100644
--- a/Makefile
+++ b/Makefile
@@ -42,4 +42,4 @@ DBDS += turboPmac/sinqMotor/src/sinqMotor.dbd
 DBDS += turboPmac/src/turboPmac.dbd
 DBDS += src/seleneGuide.dbd
 
-USR_CFLAGS += -Wall -Wextra -Weffc++ -Wunused-result -Wextra -Werror # -Wpedantic // Does not work because EPICS macros trigger warnings
+USR_CFLAGS += -Wall -Wextra -Weffc++ -Wunused-result -Wextra -Werror -fvisibility=hidden# -Wpedantic // Does not work because EPICS macros trigger warnings
diff --git a/src/seleneAngleAxis.h b/src/seleneAngleAxis.h
index 7e4063e..cbab966 100644
--- a/src/seleneAngleAxis.h
+++ b/src/seleneAngleAxis.h
@@ -6,14 +6,14 @@
 // Forward declaration of the seleneLiftAxis class to resolve the cyclic
 // dependency between the seleneLiftAxis and the seleneAngleAxis .h-file.
 // See https://en.cppreference.com/w/cpp/language/class.
-class seleneLiftAxis;
+class HIDDEN seleneLiftAxis;
 
 /**
  * @brief Virtual axis for setting the angle of the Selene guide
  *
  * Please see README.md for a detailed explanation.
  */
-class seleneAngleAxis : public turboPmacAxis {
+class HIDDEN seleneAngleAxis : public turboPmacAxis {
   public:
     /**
      * @brief Construct a new seleneAngleAxis.
diff --git a/src/seleneGuideController.h b/src/seleneGuideController.h
index 788a618..0aeef16 100644
--- a/src/seleneGuideController.h
+++ b/src/seleneGuideController.h
@@ -13,11 +13,11 @@
 // Forward declaration of the axis classes to resolve the cyclic
 // dependency between the seleneLiftAxis and the seleneAngleAxis .h-file.
 // See https://en.cppreference.com/w/cpp/language/class.
-class seleneAngleAxis;
-class seleneLiftAxis;
-class seleneOffsetAxis;
+class HIDDEN seleneAngleAxis;
+class HIDDEN seleneLiftAxis;
+class HIDDEN seleneOffsetAxis;
 
-class seleneGuideController : public turboPmacController {
+class HIDDEN seleneGuideController : public turboPmacController {
 
   public:
     /**
diff --git a/src/seleneLiftAxis.h b/src/seleneLiftAxis.h
index 53e8b4c..d92041f 100644
--- a/src/seleneLiftAxis.h
+++ b/src/seleneLiftAxis.h
@@ -11,7 +11,7 @@
  *
  * Please see README.md for a detailed explanation.
  */
-class seleneLiftAxis : public turboPmacAxis {
+class HIDDEN seleneLiftAxis : public turboPmacAxis {
   public:
     static const int numAxes_ = 6;
 
diff --git a/src/seleneOffsetAxis.h b/src/seleneOffsetAxis.h
index 84e003a..3d1a3dd 100644
--- a/src/seleneOffsetAxis.h
+++ b/src/seleneOffsetAxis.h
@@ -7,14 +7,14 @@
 // Forward declaration of the seleneLiftAxis class to resolve the cyclic
 // dependency between the seleneLiftAxis and the seleneAngleAxis .h-file.
 // See https://en.cppreference.com/w/cpp/language/class.
-class seleneLiftAxis;
+class HIDDEN seleneLiftAxis;
 
 /**
  * @brief Virtual axis for setting the offset of a motor of the Selene guide
  *
  * Please see README.md for a detailed explanation.
  */
-class seleneOffsetAxis : public turboPmacAxis {
+class HIDDEN seleneOffsetAxis : public turboPmacAxis {
   public:
     /**
      * @brief Construct a new selene Offset Axis object
diff --git a/turboPmac b/turboPmac
index f423002..d41e7bf 160000
--- a/turboPmac
+++ b/turboPmac
@@ -1 +1 @@
-Subproject commit f423002d23aa958f48c3d63dd8887439ff26ae0f
+Subproject commit d41e7bf054432959e66f2c1563a1549a5a8d89b9