diff --git a/src/devices/cpu/tms9900/tms9900.cpp b/src/devices/cpu/tms9900/tms9900.cpp
index 6f9ef5f7926..8c94a0662f8 100644
--- a/src/devices/cpu/tms9900/tms9900.cpp
+++ b/src/devices/cpu/tms9900/tms9900.cpp
@@ -341,7 +341,7 @@ void tms99xx_device::state_import(const device_state_entry &entry)
 			break;
 		default:
 			// Workspace registers
-			if (index <= TMS9900_R15)
+			if (index <= TMS9900_R15 && started())
 				write_workspace_register_debug(index-TMS9900_R0, (uint16_t)m_state_any);
 			break;
 	}
@@ -373,7 +373,7 @@ void tms99xx_device::state_export(const device_state_entry &entry)
 		default:
 			// Workspace registers
 			if (index <= TMS9900_R15)
-				m_state_any = read_workspace_register_debug(index-TMS9900_R0);
+				m_state_any = started() ? read_workspace_register_debug(index-TMS9900_R0) : 0;
 			break;
 	}
 }
diff --git a/src/devices/cpu/tms9900/tms9995.cpp b/src/devices/cpu/tms9900/tms9995.cpp
index c1b07bcbc70..6cbb64a350c 100644
--- a/src/devices/cpu/tms9900/tms9995.cpp
+++ b/src/devices/cpu/tms9900/tms9995.cpp
@@ -339,7 +339,7 @@ void tms9995_device::state_import(const device_state_entry &entry)
 			break;
 		default:
 			// Workspace registers
-			if (index <= TMS9995_R15)
+			if (index <= TMS9995_R15 && started())
 				write_workspace_register_debug(index-TMS9995_R0, (uint16_t)m_state_any);
 			break;
 	}
@@ -371,7 +371,7 @@ void tms9995_device::state_export(const device_state_entry &entry)
 		default:
 			// Workspace registers
 			if (index <= TMS9995_R15)
-				m_state_any = read_workspace_register_debug(index-TMS9995_R0);
+				m_state_any = started() ? read_workspace_register_debug(index-TMS9995_R0) : 0;
 			break;
 	}
 }