diff --git a/src/options.go b/src/options.go
index 3692f0c..699e8a5 100644
--- a/src/options.go
+++ b/src/options.go
@@ -994,7 +994,7 @@ func parsePreviewWindow(opts *previewOpts, input string) {
 	opts.wrap = false
 
 	tokens := strings.Split(input, ":")
-	sizeRegex := regexp.MustCompile("^[0-9]+%?$")
+	sizeRegex := regexp.MustCompile("^[1-9][0-9]*%?$")
 	offsetRegex := regexp.MustCompile("^\\+([0-9]+|{-?[0-9]+})(-[0-9]+)?$")
 	for _, token := range tokens {
 		switch token {