diff --git a/scope.go b/scope.go
index 57fc33b..f815501 100644
--- a/scope.go
+++ b/scope.go
@@ -78,7 +78,7 @@ func NewTxnResourceScope(owner *ResourceScope) *ResourceScope {
 // Resources implementation
 func (rc *Resources) checkMemory(rsvp int64) error {
 	// overflow check; this also has the side effect that we cannot reserve negative memory.
-	newmem := rc.memory + int64(rsvp)
+	newmem := rc.memory + rsvp
 	if newmem < rc.memory {
 		return fmt.Errorf("memory reservation overflow: %w", ErrResourceLimitExceeded)
 	}
@@ -103,7 +103,7 @@ func (rc *Resources) reserveMemory(size int64) error {
 		return err
 	}
 
-	rc.memory += int64(size)
+	rc.memory += size
 	return nil
 }