diff --git a/include/util/range_table.hpp b/include/util/range_table.hpp
index b24daa3bc..5ea5abc59 100644
--- a/include/util/range_table.hpp
+++ b/include/util/range_table.hpp
@@ -80,9 +80,9 @@ template <unsigned BLOCK_SIZE, storage::Ownership Ownership> class RangeTable
         unsigned last_length = 0;
         unsigned lengths_prefix_sum = 0;
         unsigned block_idx = 0;
-        unsigned block_counter = 0;
         BlockT block;
 #ifndef BOOST_ASSERT_IS_VOID
+        unsigned block_counter = 0;
         unsigned block_sum = 0;
 #endif
         for (const unsigned l : lengths)
@@ -110,7 +110,9 @@ template <unsigned BLOCK_SIZE, storage::Ownership Ownership> class RangeTable
             if (BLOCK_SIZE == block_idx)
             {
                 diff_blocks.push_back(block);
+#ifndef BOOST_ASSERT_IS_VOID
                 block_counter++;
+#endif
             }
 
             // we can only store strings with length 255