diff --git a/internal/multipart/types.go b/internal/multipart/types.go
index 6860af4..86fda25 100644
--- a/internal/multipart/types.go
+++ b/internal/multipart/types.go
@@ -1,21 +1,15 @@
 package multipart
 
-// ConstError is a wrapper to set constant errors
-type ConstError string
-
-// Error implements error
-func (err ConstError) Error() string {
-	return string(err)
-}
+import "git.xdrm.io/go/aicra/internal/cerr"
 
 // ErrMissingDataName is set when a multipart variable/file has no name="..."
-const ErrMissingDataName = ConstError("data has no name")
+const ErrMissingDataName = cerr.Error("data has no name")
 
 // ErrDataNameConflict is set when a multipart variable/file name is already used
-const ErrDataNameConflict = ConstError("data name conflict")
+const ErrDataNameConflict = cerr.Error("data name conflict")
 
 // ErrNoHeader is set when a multipart variable/file has no (valid) header
-const ErrNoHeader = ConstError("data has no header")
+const ErrNoHeader = cerr.Error("data has no header")
 
 // Component represents a multipart variable/file
 type Component struct {