diff --git a/include/dwarfs/options.h b/include/dwarfs/options.h
index abdde8bc..f32273d3 100644
--- a/include/dwarfs/options.h
+++ b/include/dwarfs/options.h
@@ -73,7 +73,7 @@ struct filesystem_options {
 
 struct filesystem_writer_options {
   size_t max_queue_size{64 << 20};
-  size_t max_queued_blocks{8};
+  size_t worst_case_block_size{4 << 20};
   bool remove_header{false};
   bool no_section_index{false};
 };
diff --git a/src/dwarfs/filesystem_writer.cpp b/src/dwarfs/filesystem_writer.cpp
index c3ff8522..c932f7c1 100644
--- a/src/dwarfs/filesystem_writer.cpp
+++ b/src/dwarfs/filesystem_writer.cpp
@@ -124,6 +124,23 @@ class fsblock {
   std::unique_ptr<impl> impl_;
 };
 
+class fsblock_merger_policy {
+ public:
+  fsblock_merger_policy(size_t worst_case_block_size)
+      : worst_case_block_size_{worst_case_block_size} {}
+
+  static size_t block_size(std::unique_ptr<fsblock> const& fsb) {
+    return fsb->size();
+  }
+
+  size_t worst_case_source_block_size(fragment_category /*source_id*/) const {
+    return worst_case_block_size_;
+  }
+
+ private:
+  size_t worst_case_block_size_;
+};
+
 class raw_fsblock : public fsblock::impl {
  public:
   raw_fsblock(section_type type, const block_compressor& bc,
@@ -347,7 +364,8 @@ class filesystem_writer_ final : public filesystem_writer::impl {
 
  private:
   using block_merger_type =
-      multi_queue_block_merger<fragment_category, std::unique_ptr<fsblock>>;
+      multi_queue_block_merger<fragment_category, std::unique_ptr<fsblock>,
+                               fsblock_merger_policy>;
   using block_holder_type = block_merger_type::block_holder_type;
 
   block_compressor const&
@@ -671,8 +689,9 @@ void filesystem_writer_<LoggerPolicy>::configure(
   }
 
   merger_ = std::make_unique<block_merger_type>(
-      max_active_slots, options_.max_queued_blocks, expected_categories,
-      [this](auto&& holder) { on_block_merged(std::move(holder)); });
+      max_active_slots, options_.max_queue_size, expected_categories,
+      [this](auto&& holder) { on_block_merged(std::move(holder)); },
+      fsblock_merger_policy{options_.worst_case_block_size});
 }
 
 template <typename LoggerPolicy>
diff --git a/src/mkdwarfs_main.cpp b/src/mkdwarfs_main.cpp
index 005c8508..865c47cc 100644
--- a/src/mkdwarfs_main.cpp
+++ b/src/mkdwarfs_main.cpp
@@ -888,11 +888,9 @@ int mkdwarfs_main(int argc, sys_char** argv) {
           ? 2000
           : 200;
 
-  // TODO: clean up the use of both max_queued_blocks and max_queue_size
   filesystem_writer_options fswopts;
   fswopts.max_queue_size = mem_limit;
-  fswopts.max_queued_blocks =
-      mem_limit / (UINT64_C(1) << sf_config.block_size_bits);
+  fswopts.worst_case_block_size = UINT64_C(1) << sf_config.block_size_bits;
   fswopts.remove_header = remove_header;
   fswopts.no_section_index = no_section_index;