diff --git a/src/options.h b/src/options.h
index 2e9deb01c..d76b8c445 100644
--- a/src/options.h
+++ b/src/options.h
@@ -162,7 +162,11 @@
 /** Presumed malloc size overhead for each allocation
  * to adjust allocations to be more aligned. */
 #ifndef MDBX_ASSUME_MALLOC_OVERHEAD
+#ifdef __SIZEOF_POINTER__
+#define MDBX_ASSUME_MALLOC_OVERHEAD (__SIZEOF_POINTER__ * 2u)
+#else
 #define MDBX_ASSUME_MALLOC_OVERHEAD (sizeof(void *) * 2u)
+#endif
 #elif MDBX_ASSUME_MALLOC_OVERHEAD < 0 || MDBX_ASSUME_MALLOC_OVERHEAD > 64 ||   \
     MDBX_ASSUME_MALLOC_OVERHEAD % 4
 #error MDBX_ASSUME_MALLOC_OVERHEAD must be defined in range 0..64 and be multiple of 4