diff --git a/flag.go b/flag.go
index 125c6ce..49682f2 100644
--- a/flag.go
+++ b/flag.go
@@ -434,8 +434,10 @@ func flagFromEnvOrFile(envVars []string, filePath string) (val string, ok bool)
 		}
 	}
 	for _, fileVar := range strings.Split(filePath, ",") {
-		if data, err := ioutil.ReadFile(fileVar); err == nil {
-			return string(data), true
+		if fileVar != "" {
+			if data, err := ioutil.ReadFile(fileVar); err == nil {
+				return string(data), true
+			}
 		}
 	}
 	return "", false