diff --git a/validate.go b/validate.go
index 980a4e5..2850647 100644
--- a/validate.go
+++ b/validate.go
@@ -286,7 +286,10 @@ func (ctx *ValidationContext) findSignature(el *etree.Element) (*types.Signature
 
 				c14NMethod := detachedSignedInfo.FindElement(childPath(detachedSignedInfo.Space, CanonicalizationMethodTag))
 				if c14NMethod == nil {
-					return errors.New("missing CanonicalizationMethod on Signature")
+					c14NMethod = detachedSignedInfo.FindElement(childPath("", CanonicalizationMethodTag))
+					if c14NMethod == nil {
+						return errors.New("missing CanonicalizationMethod on Signature")
+					}
 				}
 
 				c14NAlgorithm := c14NMethod.SelectAttrValue(AlgorithmAttr, "")