diff --git a/include/mimalloc-types.h b/include/mimalloc-types.h
index 3a4f8f6b..88905bdc 100644
--- a/include/mimalloc-types.h
+++ b/include/mimalloc-types.h
@@ -132,16 +132,16 @@ typedef int32_t  mi_ssize_t;
 
 // Main tuning parameters for segment and page sizes
 // Sizes for 64-bit (usually divide by two for 32-bit)
-#define MI_SEGMENT_SLICE_SHIFT            (12 + MI_INTPTR_SHIFT)         // 64KiB  (32KiB on 32-bit)
+#define MI_SEGMENT_SLICE_SHIFT            (12 + MI_INTPTR_SHIFT)         // 32KiB  (32KiB on 32-bit)
 
 #if MI_INTPTR_SIZE > 4
-#define MI_SEGMENT_SHIFT                  (10 + MI_SEGMENT_SLICE_SHIFT)  // 64MiB
+#define MI_SEGMENT_SHIFT                  (10 + MI_SEGMENT_SLICE_SHIFT)  // 32MiB
 #else
 #define MI_SEGMENT_SHIFT                  ( 7 + MI_SEGMENT_SLICE_SHIFT)  // 4MiB on 32-bit
 #endif
 
 #define MI_SMALL_PAGE_SHIFT               (MI_SEGMENT_SLICE_SHIFT)       // 64KiB
-#define MI_MEDIUM_PAGE_SHIFT              ( 3 + MI_SMALL_PAGE_SHIFT)     // 512KiB
+#define MI_MEDIUM_PAGE_SHIFT              ( 4 + MI_SMALL_PAGE_SHIFT)     // 512KiB
 
 
 // Derived constants
@@ -324,7 +324,7 @@ typedef enum mi_segment_kind_e {
 // is still tracked in fine-grained MI_COMMIT_SIZE chunks)
 // ------------------------------------------------------
 
-#define MI_MINIMAL_COMMIT_SIZE      (MI_MiB)
+#define MI_MINIMAL_COMMIT_SIZE      (2*MI_MiB)
 #define MI_COMMIT_SIZE              (MI_SEGMENT_SLICE_SIZE)              // 64KiB
 #define MI_COMMIT_MASK_BITS         (MI_SEGMENT_SIZE / MI_COMMIT_SIZE)  
 #define MI_COMMIT_MASK_FIELD_BITS    MI_SIZE_BITS
diff --git a/src/page.c b/src/page.c
index 2fa03606..cb957bf7 100644
--- a/src/page.c
+++ b/src/page.c
@@ -408,7 +408,7 @@ void _mi_page_free(mi_page_t* page, mi_page_queue_t* pq, bool force) {
 }
 
 // Retire parameters
-#define MI_MAX_RETIRE_SIZE    MI_MEDIUM_OBJ_SIZE_MAX  
+#define MI_MAX_RETIRE_SIZE    (MI_MEDIUM_OBJ_SIZE_MAX)
 #define MI_RETIRE_CYCLES      (8)
 
 // Retire a page with no more used blocks
@@ -579,7 +579,7 @@ static mi_decl_noinline void mi_page_free_list_extend( mi_page_t* const page, co
 #if (MI_SECURE>0)
 #define MI_MIN_EXTEND         (8*MI_SECURE) // extend at least by this many
 #else
-#define MI_MIN_EXTEND         (1)
+#define MI_MIN_EXTEND         (4)
 #endif
 
 // Extend the capacity (up to reserved) by initializing a free list