diff --git a/CMake/itkImageIOFactoryRegisterManager.h.in b/CMake/itkImageIOFactoryRegisterManager.h.in
index f5cd6d97eb5..9e105ec72a7 100644
--- a/CMake/itkImageIOFactoryRegisterManager.h.in
+++ b/CMake/itkImageIOFactoryRegisterManager.h.in
@@ -26,7 +26,7 @@ class ImageIOFactoryRegisterManager
   public:
   explicit ImageIOFactoryRegisterManager(void (*list[])(void))
     {
-    for(;*list; ++list)
+    for(;*list != nullptr; ++list)
       {
       (*list)();
       }
diff --git a/CMake/itkMeshIOFactoryRegisterManager.h.in b/CMake/itkMeshIOFactoryRegisterManager.h.in
index 0f0f3c1e36b..770b9cc05a2 100644
--- a/CMake/itkMeshIOFactoryRegisterManager.h.in
+++ b/CMake/itkMeshIOFactoryRegisterManager.h.in
@@ -26,7 +26,7 @@ class MeshIOFactoryRegisterManager
   public:
   explicit MeshIOFactoryRegisterManager(void (*list[])(void))
     {
-    for(;*list; ++list)
+    for(;*list != nullptr; ++list)
       {
       (*list)();
       }
diff --git a/CMake/itkTransformIOFactoryRegisterManager.h.in b/CMake/itkTransformIOFactoryRegisterManager.h.in
index 8b11587f33e..998e1f10244 100644
--- a/CMake/itkTransformIOFactoryRegisterManager.h.in
+++ b/CMake/itkTransformIOFactoryRegisterManager.h.in
@@ -26,7 +26,7 @@ class TransformIOFactoryRegisterManager
   public:
   explicit TransformIOFactoryRegisterManager(void (*list[])(void))
     {
-    for(;*list; ++list)
+    for(;*list != nullptr; ++list)
       {
       (*list)();
       }