diff --git a/ext/mdbx_ext/database.c b/ext/mdbx_ext/database.c
index 38e1c2a..ed1dd66 100644
--- a/ext/mdbx_ext/database.c
+++ b/ext/mdbx_ext/database.c
@@ -5,6 +5,8 @@
 /* VALUE str = rb_sprintf( "path: %+"PRIsVALUE", opts: %+"PRIsVALUE, path, opts ); */
 /* printf( "%s\n", StringValueCStr(str) ); */
 
+VALUE rmdbx_cDatabase;
+
 
 /* Shortcut for fetching current DB variables.
  *
@@ -45,8 +47,8 @@ static const rb_data_type_t rmdbx_db_data = {
 VALUE
 rmdbx_alloc( VALUE klass )
 {
-	rmdbx_db_t *data;
-	return TypedData_Make_Struct( klass, rmdbx_db_t, &rmdbx_db_data, data );
+	rmdbx_db_t *new = RB_ALLOC( rmdbx_db_t );
+	return TypedData_Make_Struct( klass, rmdbx_db_t, &rmdbx_db_data, new );
 }
 
 
diff --git a/ext/mdbx_ext/mdbx_ext.c b/ext/mdbx_ext/mdbx_ext.c
index 574ad90..aa4a050 100644
--- a/ext/mdbx_ext/mdbx_ext.c
+++ b/ext/mdbx_ext/mdbx_ext.c
@@ -2,6 +2,8 @@
 
 #include "mdbx_ext.h"
 
+VALUE rmdbx_mMDBX;
+VALUE rmdbx_eDatabaseError;
 
 /*
  * MDBX initialization
diff --git a/ext/mdbx_ext/mdbx_ext.h b/ext/mdbx_ext/mdbx_ext.h
index 3b5e0e4..1d4d4c1 100644
--- a/ext/mdbx_ext/mdbx_ext.h
+++ b/ext/mdbx_ext/mdbx_ext.h
@@ -12,9 +12,9 @@
  * Globals
  * ------------------------------------------------------------ */
 
-VALUE rmdbx_mMDBX;
-VALUE rmdbx_cDatabase;
-VALUE rmdbx_eDatabaseError;
+extern VALUE rmdbx_mMDBX;
+extern VALUE rmdbx_cDatabase;
+extern VALUE rmdbx_eDatabaseError;
 
 
 /* ------------------------------------------------------------