diff --git a/pkg/istr/checker.go b/pkg/istr/checker.go
index 60ada4d9..5cdc60ea 100644
--- a/pkg/istr/checker.go
+++ b/pkg/istr/checker.go
@@ -2,6 +2,7 @@ package istr
 
 import (
 	"strings"
+	"strconv"
 )
 
 func SampleKeyInvalid(str string) bool {
@@ -13,5 +14,11 @@ func SampleKeyInvalid(str string) bool {
 			r == ' ' ||
 			r == '='
 	})
-	return idx != -1
+
+	if idx != -1 {
+		return true
+	}
+
+	_, err := strconv.ParseFloat(str, 64)
+	return err == nil
 }