diff --git a/include/mcc/mcc_utils.h b/include/mcc/mcc_utils.h
index 51bab6d..4827e4c 100644
--- a/include/mcc/mcc_utils.h
+++ b/include/mcc/mcc_utils.h
@@ -68,7 +68,7 @@ constexpr static std::string_view trimSpaces(const char* r, TrimType type = Trim
 }
 
 template <typename T, std::ranges::contiguous_range R>
-std::optional<T> numFromStr(R&& r)
+static std::optional<T> numFromStr(R&& r)
     requires((std::integral<T> || std::floating_point<T>) &&
              std::same_as<char, std::remove_cvref_t<std::ranges::range_value_t<R>>>)
 {
@@ -340,7 +340,10 @@ static std::string AZZD_rad2sxg(double az, double zd, std::string_view delim = "
 // "12:43:23.423,  102:43:12.124"
 // "  12.3453467, 102:43:12.124  "
 template <mcc::traits::mcc_input_char_range R>
-std::pair<double, double> parseAnglePair(R&& str, bool hms1 = false, bool hms2 = false, std::string_view delim = ",")
+static std::pair<double, double> parseAnglePair(R&& str,
+                                                bool hms1 = false,
+                                                bool hms2 = false,
+                                                std::string_view delim = ",")
 {
     std::pair<double, double> res{std::numeric_limits<double>::quiet_NaN(), std::numeric_limits<double>::quiet_NaN()};
     auto found1 = std::ranges::search(std::forward<R>(str), delim);
@@ -382,7 +385,10 @@ std::pair<double, double> parseAnglePair(R&& str, bool hms1 = false, bool hms2 =
 //         1st element: difference along co-latitude axis
 //         2nd element: distance
 
-std::tuple<double, double, double> distanceOnSphere(double co_lon1, double co_lat1, double co_lon2, double co_lat2)
+static std::tuple<double, double, double> distanceOnSphere(double co_lon1,
+                                                           double co_lat1,
+                                                           double co_lon2,
+                                                           double co_lat2)
 {
     std::tuple<double, double, double> res{};