Google has added a section to the use rel=canonical link annotations section of the canonical search documentation to clarify that rel=canonical annotations with certain attributes are not used for canonicalization.
Google explained that "annotations with hreflang, lang, media, and type attributes are not used for canonicalization."
Google added this section:
Google supports explicit rel canonical link annotations as described in RFC 6596. rel="canonical" annotations that suggest alternate versions of a page are ignored; specifically, rel="canonical" annotations with hreflang, lang, media, and type attributes are not used for canonicalization. Instead, use the appropriate link annotations to specify alternate versions of a page; for example, link rel="alternate" hreflang for language and country annotations.
Previously it only said, "Google supports rel canonical link annotations as described in RFC 6596."
So go check your canonical annotations if you are not sure...
Forum discussion at X.