diff --git a/slob.cc b/slob.cc
index 28d829e8..ae252a00 100644
--- a/slob.cc
+++ b/slob.cc
@@ -1029,7 +1029,7 @@ void SlobDictionary::makeFTSIndex( QAtomicInt & isCancelled, bool firstIteration
     ftsIdxHeader.indexRootOffset = ftsIdxInfo.rootOffset;
 
     ftsIdxHeader.signature = FtsHelpers::FtsSignature;
-    ftsIdxHeader.formatVersion = FtsHelpers::CurrentFtsFormatVersion;
+    ftsIdxHeader.formatVersion = FtsHelpers::CurrentFtsFormatVersion + getFtsIndexVersion();
 
     ftsIdx.rewind();
     ftsIdx.writeRecords( &ftsIdxHeader, sizeof(ftsIdxHeader), 1 );
diff --git a/zim.cc b/zim.cc
index c9546a16..b9925e4b 100644
--- a/zim.cc
+++ b/zim.cc
@@ -839,7 +839,7 @@ void ZimDictionary::makeFTSIndex( QAtomicInt & isCancelled, bool firstIteration
     ftsIdxHeader.indexRootOffset = ftsIdxInfo.rootOffset;
 
     ftsIdxHeader.signature = FtsHelpers::FtsSignature;
-    ftsIdxHeader.formatVersion = FtsHelpers::CurrentFtsFormatVersion;
+    ftsIdxHeader.formatVersion = FtsHelpers::CurrentFtsFormatVersion + getFtsIndexVersion();
 
     ftsIdx.rewind();
     ftsIdx.writeRecords( &ftsIdxHeader, sizeof(ftsIdxHeader), 1 );