1 files changed, 3 insertions, 0 deletions

diff --git a/doc/lispref/errors.texi b/doc/lispref/errors.texi
index 45e7acbaa6b..cf9b67c80d8 100644
--- a/doc/lispref/errors.texi
+++ b/doc/lispref/errors.texi
@@ -215,6 +215,9 @@ The message is @samp{Wrong number of arguments}.  @xref{Argument List}.
 
 @item wrong-type-argument
 The message is @samp{Wrong type argument}.  @xref{Type Predicates}.
+
+@item unknown-image-type
+The message is @samp{Cannot determine image type}.  @xref{Images}.
 @end table
 
 @ignore    The following seem to be unused now.