diff --git a/ledger/file.go b/ledger/file.go
index 7a3465c..97895be 100644
--- a/ledger/file.go
+++ b/ledger/file.go
@@ -128,6 +128,20 @@ func (files Files) Deltas(like ...Like) (Deltas, error) {
 			}
 		}
 	}
+
+	balances := make(Balances)
+	for i := range result {
+		if result[i].isSet {
+			var was float64
+			if m, ok := balances[result[i].Name]; ok {
+				was = m[result[i].Currency]
+			}
+			result[i].Value = result[i].Value - was
+			result[i].isSet = false
+		}
+		balances.Push(result[i])
+	}
+
 	for i := range result {
 		if result[i].isSet {
 			return nil, fmt.Errorf("failed to resolve isSet: %+v", result[i])