diff --git a/scumm/script_v6.cpp b/scumm/script_v6.cpp
index 31f5eea0fb6..58b8e3043f2 100644
--- a/scumm/script_v6.cpp
+++ b/scumm/script_v6.cpp
@@ -2386,6 +2386,7 @@ void Scumm_v6::o6_kernelSetFunctions() {
 //					_imuseDigital->stopAll();
 //				}
 				uint32 speed;
+				assert(getStringAddressVar(VAR_VIDEONAME));
 				if (strcmp((char *)getStringAddressVar(VAR_VIDEONAME), "sq3.san") == 0)
 					speed = 71000;
 				else {