diff --git a/3party/opening_hours/opening_hours.cpp b/3party/opening_hours/opening_hours.cpp
index 81f7fd0997..ea603b43fc 100644
--- a/3party/opening_hours/opening_hours.cpp
+++ b/3party/opening_hours/opening_hours.cpp
@@ -96,6 +96,14 @@ class StreamFlagsKeeper
 };
 
 template <typename TNumber>
+constexpr bool IsChar(TNumber) noexcept
+{
+  return std::is_same<signed char, TNumber>::value ||
+         std::is_same<unsigned char, TNumber>::value ||
+         std::is_same<char, TNumber>::value;
+};
+
+template <typename TNumber, typename std::enable_if<!IsChar(TNumber{}), void*>::type = nullptr>
 void PrintPaddedNumber(std::ostream & ost, TNumber const number, uint32_t const padding = 1)
 {
   static_assert(std::is_integral<TNumber>::value, "number should be of integral type.");
@@ -103,6 +111,12 @@ void PrintPaddedNumber(std::ostream & ost, TNumber const number, uint32_t const
   ost << std::setw(padding) << std::setfill('0') << number;
 }
 
+template <typename TNumber, typename std::enable_if<IsChar(TNumber{}), void*>::type = nullptr>
+void PrintPaddedNumber(std::ostream & ost, TNumber const number, uint32_t const padding = 1)
+{
+  PrintPaddedNumber(ost, static_cast<int32_t>(number), padding);
+}
+
 void PrintHoursMinutes(std::ostream & ost,
                        std::chrono::hours::rep hours,
                        std::chrono::minutes::rep minutes)