diff --git a/contrib/jemalloc-cmake/CMakeLists.txt b/contrib/jemalloc-cmake/CMakeLists.txt
index 0bbb1e87ffc8..63194b6b0bb5 100644
--- a/contrib/jemalloc-cmake/CMakeLists.txt
+++ b/contrib/jemalloc-cmake/CMakeLists.txt
@@ -35,18 +35,13 @@ if (OS_LINUX)
     # MADV_DONTNEED. See
     # https://github.com/ClickHouse/ClickHouse/issues/11121 for motivation.
     #
-    # lg_extent_max_active_fit:8 controls how jemalloc reuses memory blocks.
-    # Value 8 means extents can be reused when their size is up to 2^8 (256) times larger than requested.
-    # This enables better hot dirty memory reuse for two-level hashtables with 256 sub-hashtables.
-    # In ClickBench queries (e.g. Q35), these 256 sub-hashtables (16KB each) get reallocated frequently.
-    # Without this setting, when multiple 16KB blocks coalesce into larger blocks (>64*16KB),
-    # they can't be reused for new 16KB requests, causing expensive page faults from MADV_DONTNEED.
-    # Increasing from default 6(64x) to 8(256x) allows these coalesced blocks to be split and reused.
-    # See: https://github.com/ClickHouse/ClickHouse/pull/80245
-    # https://github.com/jemalloc/jemalloc/pull/2842
-    set (JEMALLOC_CONFIG_MALLOC_CONF "percpu_arena:percpu,oversize_threshold:0,muzzy_decay_ms:0,dirty_decay_ms:5000,prof:true,prof_active:false,background_thread:true,lg_extent_max_active_fit:8")
+    # Use jemalloc's default maximum extent reuse ratio, 2^6 (64).
+    # Previously increased to 8 for ClickBench Q35, but that can
+    # significantly increase fragmentation.
+    # https://github.com/ClickHouse/ClickHouse/pull/116836
+    set (JEMALLOC_CONFIG_MALLOC_CONF "percpu_arena:percpu,oversize_threshold:0,muzzy_decay_ms:0,dirty_decay_ms:5000,prof:true,prof_active:false,background_thread:true,lg_extent_max_active_fit:6")
 else()
-    set (JEMALLOC_CONFIG_MALLOC_CONF "oversize_threshold:0,muzzy_decay_ms:0,dirty_decay_ms:5000,lg_extent_max_active_fit:8")
+    set (JEMALLOC_CONFIG_MALLOC_CONF "oversize_threshold:0,muzzy_decay_ms:0,dirty_decay_ms:5000,lg_extent_max_active_fit:6")
 endif()
 # CACHE variable is empty to allow changing defaults without the necessity
 # to purge cache