diff --git a/src/transformers/_common/parties.ts b/src/transformers/_common/parties.ts
index 8e8bc48..adcca73 100644
--- a/src/transformers/_common/parties.ts
+++ b/src/transformers/_common/parties.ts
@@ -20,7 +20,9 @@ export function transform(block: RawBlock): RawBlock {
     const inputAddresses: string[] = tx.decoded
       ? tx.decoded.decoded
           .map((param) =>
-            param.type === 'address' ? param.decoded.toLowerCase() : '',
+            param.type === 'address' && param.decoded
+              ? param.decoded.toLowerCase()
+              : '',
           )
           .filter((address) => address !== '')
       : [];
@@ -42,7 +44,9 @@ export function transform(block: RawBlock): RawBlock {
       // grab event inputs params from decoded trace
       const partiesFromTrace = trace.decoded?.decoded
         .map((param) =>
-          param.type === 'address' ? param.decoded.toLowerCase() : '',
+          param.type === 'address' && param.decoded
+            ? param.decoded.toLowerCase()
+            : '',
         )
         .filter((address) => address !== '');
 
@@ -57,7 +61,9 @@ export function transform(block: RawBlock): RawBlock {
       // grab event inputs params from decoded log
       const partiesFromLog = log.decoded?.decoded
         .map((param) =>
-          param.type === 'address' ? param.decoded.toLowerCase() : '',
+          param.type === 'address' && param.decoded
+            ? param.decoded.toLowerCase()
+            : '',
         )
         .filter((address) => address !== '');