diff --git a/src/ZoneCodeGeneratorLib/Generating/Templates/ZoneWriteTemplate.cpp b/src/ZoneCodeGeneratorLib/Generating/Templates/ZoneWriteTemplate.cpp
index 0c9f2da2..a8d21d53 100644
--- a/src/ZoneCodeGeneratorLib/Generating/Templates/ZoneWriteTemplate.cpp
+++ b/src/ZoneCodeGeneratorLib/Generating/Templates/ZoneWriteTemplate.cpp
@@ -486,16 +486,23 @@ namespace
             else if (member->m_type && !member->m_type->m_has_matching_cross_platform_structure)
             {
                 LINEF("const auto fillArraySize = static_cast<size_t>({0});", MakeEvaluation(modifier.GetArrayPointerCountEvaluation()))
-                LINEF("const auto fill = m_stream->WriteWithFill({0} * fillArraySize);", member->m_member->m_type_declaration->m_type->GetSize())
-                LINE("for (auto i = 0uz; i < fillArraySize; i++)")
-                LINE("{")
-                m_intendation++;
-                LINEF("{0} = &{1}[i];", MakeTypeVarName(member->m_type->m_definition), MakeMemberAccess(info, member, modifier))
-                LINEF("FillStruct_{0}(fill.AtOffset(i * {1}));",
-                      MakeSafeTypeName(member->m_type->m_definition),
-                      member->m_member->m_type_declaration->m_type->GetSize())
-                m_intendation--;
-                LINE("}")
+                if (!computations.IsInRuntimeBlock())
+                {
+                    LINEF("const auto fill = m_stream->WriteWithFill({0} * fillArraySize);", member->m_member->m_type_declaration->m_type->GetSize())
+                    LINE("for (auto i = 0uz; i < fillArraySize; i++)")
+                    LINE("{")
+                    m_intendation++;
+                    LINEF("{0} = &{1}[i];", MakeTypeVarName(member->m_type->m_definition), MakeMemberAccess(info, member, modifier))
+                    LINEF("FillStruct_{0}(fill.AtOffset(i * {1}));",
+                          MakeSafeTypeName(member->m_type->m_definition),
+                          member->m_member->m_type_declaration->m_type->GetSize())
+                    m_intendation--;
+                    LINE("}")
+                }
+                else
+                {
+                    LINEF("m_stream->IncBlockPos({0} * fillArraySize);", member->m_member->m_type_declaration->m_type->GetSize())
+                }
             }
             else
             {
diff --git a/src/ZoneWriting/Zone/Stream/ZoneOutputStream.cpp b/src/ZoneWriting/Zone/Stream/ZoneOutputStream.cpp
index 6806f2fe..e7dd69d7 100644
--- a/src/ZoneWriting/Zone/Stream/ZoneOutputStream.cpp
+++ b/src/ZoneWriting/Zone/Stream/ZoneOutputStream.cpp
@@ -360,10 +360,12 @@ ZoneStreamFillWriteAccessor::ZoneStreamFillWriteAccessor(void* blockBuffer, cons
 
 ZoneStreamFillWriteAccessor ZoneStreamFillWriteAccessor::AtOffset(const size_t offset) const
 {
+    assert(m_block_buffer);
     return ZoneStreamFillWriteAccessor(static_cast<char*>(m_block_buffer) + offset, m_buffer_size - offset);
 }
 
 ZoneOutputOffset ZoneStreamFillWriteAccessor::Offset() const
 {
+    assert(m_block_buffer);
     return ZoneOutputOffset(m_block_buffer);
 }
diff --git a/src/ZoneWriting/Zone/Stream/ZoneOutputStream.h b/src/ZoneWriting/Zone/Stream/ZoneOutputStream.h
index b9d67d13..8dba427b 100644
--- a/src/ZoneWriting/Zone/Stream/ZoneOutputStream.h
+++ b/src/ZoneWriting/Zone/Stream/ZoneOutputStream.h
@@ -36,6 +36,7 @@ public:
 
     template<typename T> void Fill(const T& value, const size_t offset) const
     {
+        assert(m_block_buffer);
         assert(offset + sizeof(T) <= m_buffer_size);
 
         *reinterpret_cast<T*>(static_cast<char*>(m_block_buffer) + offset) = value;
@@ -43,6 +44,7 @@ public:
 
     template<typename T, size_t S> void FillArray(T (&value)[S], const size_t offset) const
     {
+        assert(m_block_buffer);
         assert(offset + sizeof(T) * S <= m_buffer_size);
 
         std::memcpy(static_cast<char*>(m_block_buffer) + offset, value, sizeof(T) * S);