diff --git a/src/mame/drivers/svi318.cpp b/src/mame/drivers/svi318.cpp
index 4a6396cb80a..c13f0a56d59 100644
--- a/src/mame/drivers/svi318.cpp
+++ b/src/mame/drivers/svi318.cpp
@@ -92,9 +92,9 @@ protected:
 	optional_device<palette_device> m_palette;
 
 private:
-	required_memory_bank m_bank1;
-	required_memory_bank m_bank2;
-	required_memory_bank m_bank3;
+	optional_memory_bank m_bank1;
+	optional_memory_bank m_bank2;
+	optional_memory_bank m_bank3;
 	optional_memory_bank m_bank4;
 };