diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index 299e86076..ebb76ec76 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -135,6 +135,12 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     ds.brokenShortcutSlides=false;
     ds.ignoreDuplicateSlides=true;
 
+    // 1.1 compat flags
+    if (ds.version>24) {
+      ds.waveDutyIsVol=true;
+      ds.legacyVolumeSlides=false;
+    }
+
     // Neo Geo detune
     if (ds.system[0]==DIV_SYSTEM_YM2610 || ds.system[0]==DIV_SYSTEM_YM2610_EXT) {
       ds.tuning=443.23;