diff --git a/docker/test/performance-comparison/config/users.d/perf-comparison-tweaks-users.xml b/docker/test/performance-comparison/config/users.d/perf-comparison-tweaks-users.xml
index 41bc7f777bf..63e23d8453c 100644
--- a/docker/test/performance-comparison/config/users.d/perf-comparison-tweaks-users.xml
+++ b/docker/test/performance-comparison/config/users.d/perf-comparison-tweaks-users.xml
@@ -17,6 +17,9 @@
 
             <!-- One NUMA node w/o hyperthreading -->
             <max_threads>12</max_threads>
+
+            <!-- mmap shows some improvements in perf tests -->
+            <min_bytes_to_use_mmap_io>64Mi</min_bytes_to_use_mmap_io>
         </default>
     </profiles>
     <users>
diff --git a/src/Core/Settings.h b/src/Core/Settings.h
index a0ec6d68986..131e8561eb5 100644
--- a/src/Core/Settings.h
+++ b/src/Core/Settings.h
@@ -142,7 +142,7 @@ class IColumn;
     M(UInt64, optimize_min_equality_disjunction_chain_length, 3, "The minimum length of the expression `expr = x1 OR ... expr = xN` for optimization ", 0) \
     \
     M(UInt64, min_bytes_to_use_direct_io, 0, "The minimum number of bytes for reading the data with O_DIRECT option during SELECT queries execution. 0 - disabled.", 0) \
-    M(UInt64, min_bytes_to_use_mmap_io, (64 * 1024 * 1024), "The minimum number of bytes for reading the data with mmap option during SELECT queries execution. 0 - disabled.", 0) \
+    M(UInt64, min_bytes_to_use_mmap_io, 0, "The minimum number of bytes for reading the data with mmap option during SELECT queries execution. 0 - disabled.", 0) \
     M(Bool, checksum_on_read, true, "Validate checksums on reading. It is enabled by default and should be always enabled in production. Please do not expect any benefits in disabling this setting. It may only be used for experiments and benchmarks. The setting only applicable for tables of MergeTree family. Checksums are always validated for other table engines and when receiving data over network.", 0) \
     \
     M(Bool, force_index_by_date, 0, "Throw an exception if there is a partition key in a table, and it is not used.", 0) \