diff --git a/src/lmdb/database.cpp b/src/lmdb/database.cpp
index c6b244671..ccab1902a 100644
--- a/src/lmdb/database.cpp
+++ b/src/lmdb/database.cpp
@@ -46,7 +46,7 @@ namespace lmdb
 {
     namespace
     {
-        constexpr const std::size_t max_resize = 1 * 1024 * 1024 * 1024; // 1 GB
+        constexpr const mdb_size_t max_resize = 1 * 1024 * 1024 * 1024; // 1 GB
         void acquire_context(context& ctx) noexcept
         {
             while (ctx.lock.test_and_set());
@@ -136,7 +136,7 @@ namespace lmdb
         MDB_envinfo info{};
         MONERO_LMDB_CHECK(mdb_env_info(handle(), &info));
 
-        const std::size_t resize = std::min(info.me_mapsize, max_resize);
+        const mdb_size_t resize = std::min(info.me_mapsize, max_resize);
         const int err = mdb_env_set_mapsize(handle(), info.me_mapsize + resize);
         ctx.lock.clear();
         if (err)
diff --git a/src/lmdb/value_stream.cpp b/src/lmdb/value_stream.cpp
index 1024deb06..604140e47 100644
--- a/src/lmdb/value_stream.cpp
+++ b/src/lmdb/value_stream.cpp
@@ -36,9 +36,9 @@ namespace lmdb
 {
     namespace stream
     {
-        std::size_t count(MDB_cursor* cur)
+        mdb_size_t count(MDB_cursor* cur)
         {
-            std::size_t out = 0;
+            mdb_size_t out = 0;
             if (cur)
             {
                 const int rc = mdb_cursor_count(cur, &out);
diff --git a/src/lmdb/value_stream.h b/src/lmdb/value_stream.h
index c9977221f..01090aa67 100644
--- a/src/lmdb/value_stream.h
+++ b/src/lmdb/value_stream.h
@@ -43,7 +43,7 @@ namespace lmdb
             \throw std::system_error if unexpected LMDB error.
             \return 0 if `cur == nullptr`, otherwise count of values at current key.
         */
-        std::size_t count(MDB_cursor* cur);
+        mdb_size_t count(MDB_cursor* cur);
 
         /*!
             Calls `mdb_cursor_get` and does some error checking.