diff --git a/fpdf.go b/fpdf.go
index 7bccda7..a717b44 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -3496,7 +3496,7 @@ func (f *Fpdf) getpagesizestr(sizeStr string) (size SizeType) {
 		for i := 0; i <= 1; i++ {
 			aFloat[i], aErr = strconv.ParseFloat(aString[i], 64)
 			if aErr != nil {
-				f.err = fmt.Errorf("unknown page size %s", sizeStr)
+				f.err = fmt.Errorf("anknown page size %s", sizeStr)
 			}
 		}
 		size, ok = SizeType{aFloat[0], aFloat[1]}, true