diff --git a/biojava3-structure/src/main/java/org/biojava/bio/structure/align/util/AtomCache.java b/biojava3-structure/src/main/java/org/biojava/bio/structure/align/util/AtomCache.java
index <HASH>..<HASH> 100644
--- a/biojava3-structure/src/main/java/org/biojava/bio/structure/align/util/AtomCache.java
+++ b/biojava3-structure/src/main/java/org/biojava/bio/structure/align/util/AtomCache.java
@@ -168,7 +168,7 @@ public class AtomCache {
 
 		strictSCOP = true;
 
-		useMmCif = false;
+		useMmCif = true;
 
 	}
Fix #<I>. Use mmCIF as default structure format