diff --git a/include/itlib/poly_span.hpp b/include/itlib/poly_span.hpp
index 3adeba9..5c45eb1 100644
--- a/include/itlib/poly_span.hpp
+++ b/include/itlib/poly_span.hpp
@@ -194,7 +194,7 @@ class poly_span
     template <typename CRT>
     class t_iterator
     {
-        byte_t* p = 0;
+        byte_t* p = nullptr;
         size_t stride = 1;
         poly_func_t poly_func = nullptr;
 
diff --git a/include/itlib/stride_span.hpp b/include/itlib/stride_span.hpp
index 1a8480c..e6743e4 100644
--- a/include/itlib/stride_span.hpp
+++ b/include/itlib/stride_span.hpp
@@ -190,7 +190,7 @@ class stride_span
     template <typename CT>
     class t_iterator
     {
-        byte_t* p = 0;
+        byte_t* p = nullptr;
         size_t stride = sizeof(T);
 
         friend class stride_span;