diff --git a/internal/log/helpers_test.go b/internal/log/helpers_test.go
index 24a6c7fa96..4db8a2bdd3 100644
--- a/internal/log/helpers_test.go
+++ b/internal/log/helpers_test.go
@@ -4,7 +4,12 @@
 package log
 
 // RFC3339 format
-const timePrefixRegex = `^2[0-9]{3}-[0-1][0-9]-[0-3][0-9]T[0-2][0-9]:[0-5][0-9]:[0-5][0-9]Z `
+const timePrefixRegex = `([0-9]+)-` +
+	`(0[1-9]|1[012])-` +
+	`(0[1-9]|[12][0-9]|3[01])[Tt]([01][0-9]|2[0-3])` +
+	`:([0-5][0-9])` +
+	`:([0-5][0-9]|60)(\.[0-9]+)?(([Zz])|([\+|\-]([01][0-9]|2[0-3])` +
+	`:[0-5][0-9])) `
 
 func levelPtr(l Level) *Level { return &l }