diff --git a/aeon_ddl.proto b/aeon_ddl.proto
index a92b828..4f394c0 100644
--- a/aeon_ddl.proto
+++ b/aeon_ddl.proto
@@ -23,6 +23,8 @@ message CreateSpaceRequest {
   repeated FieldDef format = 2;
   // Sorting key definition (indexed fields).
   repeated KeyPartDef key_def = 3;
+  // Storage engine.
+  Engine engine = 4;
 }
 
 message CreateSpaceResponse {
diff --git a/aeon_schema.proto b/aeon_schema.proto
index a1fa02f..2640bbd 100644
--- a/aeon_schema.proto
+++ b/aeon_schema.proto
@@ -31,6 +31,12 @@ message Operation {
   Tuple tuple = 3;
 }
 
+// Storage engine.
+enum Engine {
+  ENGINE_MEMTX = 0;
+  ENGINE_VINYL = 1;
+}
+
 // Type a space field can have.
 enum FieldType {
   FIELD_TYPE_UNSPECIFIED = 0;