diff --git a/platform/Utc.roc b/platform/Utc.roc
index c5085f40..12f82934 100644
--- a/platform/Utc.roc
+++ b/platform/Utc.roc
@@ -48,7 +48,7 @@ fromNanosSinceEpoch = @Utc
 ## Calculate milliseconds between two Utc timestamps
 deltaAsMillis : Utc, Utc -> U128
 deltaAsMillis = \utcA, utcB ->
-    (deltaAsNanons utcA utcB) // nanosPerMilli
+    (deltaAsNanos utcA utcB) // nanosPerMilli
 
 ## Calculate nanoseconds between two Utc timestamps
 deltaAsNanos : Utc, Utc -> U128