diff --git a/lib/config.js b/lib/config.js
index ed257b8e2..e022732d7 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -169,6 +169,7 @@ module.exports.parse_interval = function(interval) {
 	var result = 0
 	var last_suffix = Infinity
 	interval.split(/\s+/).forEach(function(x) {
+		if (!x) return
 		var m = x.match(/^((0|[1-9][0-9]*)(\.[0-9]+)?)(ms|s|m|h|d|w|M|y|)$/)
 		if (!m
 		||  parse_interval_table[m[4]] >= last_suffix
diff --git a/test/unit/parse_interval.js b/test/unit/parse_interval.js
index b0a0c2dd5..4b35a2942 100644
--- a/test/unit/parse_interval.js
+++ b/test/unit/parse_interval.js
@@ -29,5 +29,6 @@ describe('Parse interval', function() {
 	add_test('1m 1m', null)
 	add_test('1m 1y', null)
 	add_test('1y 1M 1w 1d 1h 1m 1s 1ms', 34822861001)
+	add_test(' 5s  25ms  ', 5025)
 })