diff --git a/src/main/java/com/conveyal/r5/transit/TransitLayer.java b/src/main/java/com/conveyal/r5/transit/TransitLayer.java
index 5216f89a4..e7b8f0833 100644
--- a/src/main/java/com/conveyal/r5/transit/TransitLayer.java
+++ b/src/main/java/com/conveyal/r5/transit/TransitLayer.java
@@ -558,7 +558,11 @@ public void loadFromGtfs (GTFSFeed gtfs, LoadLevel level) throws DuplicateFeedEx
         }
 
         if (level == LoadLevel.FULL) {
-            this.fares = new HashMap<>(gtfs.fares);
+            if (this.fares == null) {
+                this.fares = new HashMap<>(gtfs.fares);
+            } else {
+                this.fares.putAll(gtfs.fares);
+            }
         }
 
         // Will be useful in naming patterns.