diff --git a/src/emu/sound/ymz280b.c b/src/emu/sound/ymz280b.c
index 015bcdaa7ed..0542d17b2c4 100644
--- a/src/emu/sound/ymz280b.c
+++ b/src/emu/sound/ymz280b.c
@@ -19,9 +19,9 @@
   Voice signal is output in stereo 16-bit 2's complement MSB-first format
 
   TODO:
-  - Is memory handling 100% correct? At the moment, Konami firebeat.c is the only
-    hardware currently emulated that uses external handlers.
-    It also happens to be the only one using 16-bit PCM.
+  - Is memory handling 100% correct? At the moment, Konami firebeat.c and Scorpion bfm_sc4/5.c
+    are the only hardware currently emulated that use external handlers.
+    Konami firebeat.c also happens to be the only one using 16-bit PCM.
 
 */
 
@@ -823,6 +823,8 @@ void ymz280b_device::write_to_register(int data)
 
 			case 0x86:      /* ROM readback / RAM write (low) -> update latch */
 				m_ext_mem_address = m_ext_mem_address_hi | m_ext_mem_address_mid | data;
+				if (m_ext_mem_enable)
+					m_ext_readlatch = ymz280b_read_memory(m_ext_mem_address);
 				break;
 
 			case 0x87:      /* RAM write */