diff --git a/Modules/Core/Common/include/itkImageConstIteratorWithIndex.h b/Modules/Core/Common/include/itkImageConstIteratorWithIndex.h
index b6aa1be39a5..fef76af9cff 100644
--- a/Modules/Core/Common/include/itkImageConstIteratorWithIndex.h
+++ b/Modules/Core/Common/include/itkImageConstIteratorWithIndex.h
@@ -287,15 +287,15 @@ class ITK_TEMPLATE_EXPORT ImageConstIteratorWithIndex
 protected: // made protected so other iterators can access
   typename TImage::ConstWeakPointer m_Image;
 
-  IndexType m_PositionIndex; // Index where we currently are
-  IndexType m_BeginIndex;    // Index to start iterating over
-  IndexType m_EndIndex;      // Index to finish iterating:
-                             // one pixel past the end of each
-                             // row, col, slice, etc....
+  IndexType m_PositionIndex{ { 0 } }; // Index where we currently are
+  IndexType m_BeginIndex{ { 0 } };    // Index to start iterating over
+  IndexType m_EndIndex{ { 0 } };      // Index to finish iterating:
+                                      // one pixel past the end of each
+                                      // row, col, slice, etc....
 
   RegionType m_Region; // region to iterate over
 
-  OffsetValueType m_OffsetTable[ImageDimension + 1];
+  OffsetValueType m_OffsetTable[ImageDimension + 1]{};
 
   const InternalPixelType * m_Position;
   const InternalPixelType * m_Begin;
diff --git a/Modules/Core/Common/include/itkImageConstIteratorWithOnlyIndex.h b/Modules/Core/Common/include/itkImageConstIteratorWithOnlyIndex.h
index 89e667b13ed..3c3db6c28e1 100644
--- a/Modules/Core/Common/include/itkImageConstIteratorWithOnlyIndex.h
+++ b/Modules/Core/Common/include/itkImageConstIteratorWithOnlyIndex.h
@@ -256,15 +256,15 @@ class ITK_TEMPLATE_EXPORT ImageConstIteratorWithOnlyIndex
 protected: // made protected so other iterators can access
   typename TImage::ConstPointer m_Image;
 
-  IndexType m_PositionIndex; // Index where we currently are
-  IndexType m_BeginIndex;    // Index to start iterating over
-  IndexType m_EndIndex;      // Index to finish iterating:
-                             // one pixel past the end of each
-                             // row, col, slice, etc....
+  IndexType m_PositionIndex{ { 0 } }; // Index where we currently are
+  IndexType m_BeginIndex{ { 0 } };    // Index to start iterating over
+  IndexType m_EndIndex{ { 0 } };      // Index to finish iterating:
+                                      // one pixel past the end of each
+                                      // row, col, slice, etc....
 
   RegionType m_Region; // region to iterate over
 
-  OffsetValueType m_OffsetTable[ImageDimension + 1];
+  OffsetValueType m_OffsetTable[ImageDimension + 1]{};
 
   bool m_Remaining;
 };