diff --git a/api/http/indigo_service/jsonapi.py b/api/http/indigo_service/jsonapi.py
index 0847195127..356ae658b3 100644
--- a/api/http/indigo_service/jsonapi.py
+++ b/api/http/indigo_service/jsonapi.py
@@ -188,7 +188,7 @@ class CompoundPair(GenericModel, Generic[OutputFormatT]):
 
 
 def make_compound_response(
-    value: str, compound_format: CompoundFormat, original_format: str
+    value: str, compound_format: CompoundFormat
 ) -> CompoundResponse:
     if compound_format == CompoundFormat.AUTO:
         raise RuntimeError(
@@ -199,7 +199,7 @@ def make_compound_response(
         **{
             "data": {
                 "type": "compound",
-                "attributes": {"structure": value, "format": compound_format, "original_format": original_format},
+                "attributes": {"structure": value, "format": compound_format},
             }
         }
     )
diff --git a/api/http/indigo_service/service.py b/api/http/indigo_service/service.py
index 251f93e171..d6d478c3ac 100644
--- a/api/http/indigo_service/service.py
+++ b/api/http/indigo_service/service.py
@@ -73,19 +73,18 @@ def to_string(
     if string_format == jsonapi.CompoundFormat.AUTO:
         string_format = jsonapi.CompoundFormat.MOLFILE
 
-    original_format = compound.getOriginalFormat()
     if string_format == jsonapi.CompoundFormat.SMILES:
-        return compound.smiles(), string_format, original_format
+        return compound.smiles(), string_format
     if string_format == jsonapi.CompoundFormat.MOLFILE:
-        return compound.molfile(), string_format, original_format
+        return compound.molfile(), string_format
     if string_format == jsonapi.CompoundFormat.CML:
-        return compound.cml(), string_format, original_format
+        return compound.cml(), string_format
     if string_format == jsonapi.CompoundFormat.SMARTS:
-        return compound.smarts(), string_format, original_format
+        return compound.smarts(), string_format
     if string_format == jsonapi.CompoundFormat.KET:
-        return compound.json(), string_format, original_format
+        return compound.json(), string_format
     if string_format == jsonapi.CompoundFormat.INCHI:
-        return IndigoInchi(indigo()).getInchi(compound), string_format, original_format
+        return IndigoInchi(indigo()).getInchi(compound), string_format
     raise RuntimeError(f"{string_format} is not supported")