diff --git a/mdbx.h++ b/mdbx.h++
index 263526c2..b72e0ccb 100644
--- a/mdbx.h++
+++ b/mdbx.h++
@@ -2960,6 +2960,18 @@ public:
     inline geometry &make_fixed(intptr_t size) noexcept;
     inline geometry &make_dynamic(intptr_t lower = minimal_value,
                                   intptr_t upper = maximal_value) noexcept;
+    MDBX_CXX11_CONSTEXPR geometry() noexcept {}
+    MDBX_CXX11_CONSTEXPR
+    geometry(const geometry &) noexcept = default;
+    MDBX_CXX11_CONSTEXPR geometry(intptr_t size_lower,
+                                  intptr_t size_now = default_value,
+                                  intptr_t size_upper = maximal_value,
+                                  intptr_t growth_step = default_value,
+                                  intptr_t shrink_threshold = default_value,
+                                  intptr_t pagesize = default_value) noexcept
+        : size_lower(size_lower), size_now(size_now), size_upper(size_upper),
+          growth_step(growth_step), shrink_threshold(shrink_threshold),
+          pagesize(pagesize) {}
   };
 
   /// \brief Operation mode.