diff --git a/src/data/StructLayout.cpp b/src/data/StructLayout.cpp
index 4f5368dd..91cae4f6 100644
--- a/src/data/StructLayout.cpp
+++ b/src/data/StructLayout.cpp
@@ -260,6 +260,9 @@ size_t StructLayout::setAscii(
     auto ptr = reinterpret_cast<char*>(dst + field.offset);
     auto size = std::min(value.size(), static_cast<std::size_t>(field.elements));
     std::memcpy(ptr, value.data(), size);
+    if (size < field.elements) {
+        std::memset(ptr + size, 0, field.elements - size);
+    }
     return size;
 }
 
@@ -274,7 +277,7 @@ size_t StructLayout::setUnicode(
     auto ptr = reinterpret_cast<char*>(dst + field.offset);
     std::memcpy(ptr, value.data(), size);
     if (size < field.elements) {
-        ptr[size] = '\0';
+        std::memset(ptr + size, 0, field.elements - size);
     }
     return size;
 }
diff --git a/src/util/SmallHeap.hpp b/src/util/SmallHeap.hpp
index 3774e064..8a6ff929 100644
--- a/src/util/SmallHeap.hpp
+++ b/src/util/SmallHeap.hpp
@@ -15,7 +15,6 @@ namespace util {
         return dataio::le2h(*(reinterpret_cast<const T*>(src) + offset));
     }
 
-    // TODO: make it safer (minimize raw temporary pointers use)
     /// @brief Simple heap implementation for memory-optimal sparse array of 
     /// small different structures
     /// @note alignment is not impemented