diff --git a/Lib/fontTools/varLib/__init__.py b/Lib/fontTools/varLib/__init__.py
index 46834f643..6e101d414 100644
--- a/Lib/fontTools/varLib/__init__.py
+++ b/Lib/fontTools/varLib/__init__.py
@@ -752,10 +752,14 @@ def _add_BASE(font, masterModel, master_ttfs, axisTags):
 
 
 def _merge_OTL(font, model, master_fonts, axisTags):
+    otl_tags = ["GSUB", "GDEF", "GPOS"]
+    if not any(tag in font for tag in otl_tags):
+        return
+
     log.info("Merging OpenType Layout tables")
     merger = VariationMerger(model, axisTags, font)
 
-    merger.mergeTables(font, master_fonts, ["GSUB", "GDEF", "GPOS"])
+    merger.mergeTables(font, master_fonts, otl_tags)
     store = merger.store_builder.finish()
     if not store:
         return