diff --git a/core/state/state_object.go b/core/state/state_object.go
index 1ffb7eb40..bc1ca1f40 100644
--- a/core/state/state_object.go
+++ b/core/state/state_object.go
@@ -49,7 +49,7 @@ func (s Storage) String() (str string) {
 }
 
 func (s Storage) Copy() Storage {
-	cpy := make(Storage)
+	cpy := make(Storage, len(s))
 	for key, value := range s {
 		cpy[key] = value
 	}
diff --git a/eth/tracers/logger/logger.go b/eth/tracers/logger/logger.go
index bd326daaf..07aa2f2b4 100644
--- a/eth/tracers/logger/logger.go
+++ b/eth/tracers/logger/logger.go
@@ -40,7 +40,7 @@ type Storage map[common.Hash]common.Hash
 
 // Copy duplicates the current storage.
 func (s Storage) Copy() Storage {
-	cpy := make(Storage)
+	cpy := make(Storage, len(s))
 	for key, value := range s {
 		cpy[key] = value
 	}