diff --git a/src/governance/validators.cpp b/src/governance/validators.cpp
index 13c3ffc9eb..af89b6adc4 100644
--- a/src/governance/validators.cpp
+++ b/src/governance/validators.cpp
@@ -100,7 +100,7 @@ bool CProposalValidator::ValidateName()
 
     static constexpr std::string_view strAllowedChars{"-_abcdefghijklmnopqrstuvwxyz0123456789"};
 
-    std::transform(strName.begin(), strName.end(), strName.begin(), ToLower);
+    strName = ToLower(strName);
 
     if (strName.find_first_not_of(strAllowedChars) != std::string::npos) {
         strErrorMessages += "name contains invalid characters;";
diff --git a/src/netbase.cpp b/src/netbase.cpp
index 83e128f606..680c3ac2a9 100644
--- a/src/netbase.cpp
+++ b/src/netbase.cpp
@@ -42,8 +42,8 @@ bool fNameLookup = DEFAULT_NAME_LOOKUP;
 static const int SOCKS5_RECV_TIMEOUT = 20 * 1000;
 static std::atomic<bool> interruptSocks5Recv(false);
 
-enum Network ParseNetwork(std::string net) {
-    Downcase(net);
+enum Network ParseNetwork(const std::string& net_in) {
+    std::string net = ToLower(net_in);
     if (net == "ipv4") return NET_IPV4;
     if (net == "ipv6") return NET_IPV6;
     if (net == "onion") return NET_ONION;
diff --git a/src/netbase.h b/src/netbase.h
index 7dc0992822..fa57b5914c 100644
--- a/src/netbase.h
+++ b/src/netbase.h
@@ -38,7 +38,7 @@ public:
     bool randomize_credentials;
 };
 
-enum Network ParseNetwork(std::string net);
+enum Network ParseNetwork(const std::string& net);
 std::string GetNetworkName(enum Network net);
 bool SetProxy(enum Network net, const proxyType &addrProxy);
 bool GetProxy(enum Network net, proxyType &proxyInfoOut);
diff --git a/src/rpc/masternode.cpp b/src/rpc/masternode.cpp
index 8a11dc91e6..e1dddafb5a 100644
--- a/src/rpc/masternode.cpp
+++ b/src/rpc/masternode.cpp
@@ -564,7 +564,7 @@ static UniValue masternodelist(const JSONRPCRequest& request)
     if (!request.params[0].isNull()) strMode = request.params[0].get_str();
     if (!request.params[1].isNull()) strFilter = request.params[1].get_str();
 
-    std::transform(strMode.begin(), strMode.end(), strMode.begin(), ToLower);
+    strMode = ToLower(strMode);
 
     if (request.fHelp || (
                 strMode != "addr" && strMode != "full" && strMode != "info" && strMode != "json" &&
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
index 80cf9fc556..569d15a569 100644
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -188,7 +188,7 @@ bool ParseBoolV(const UniValue& v, const std::string &strName)
     else if (v.isStr())
         strBool = v.get_str();
 
-    std::transform(strBool.begin(), strBool.end(), strBool.begin(), ToLower);
+    strBool = ToLower(strBool);
 
     if (strBool == "true" || strBool == "yes" || strBool == "1") {
         return true;
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index 72a7a4a182..9362f662d4 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -1325,17 +1325,9 @@ BOOST_AUTO_TEST_CASE(test_ToLower)
     BOOST_CHECK_EQUAL(ToLower(0), 0);
     BOOST_CHECK_EQUAL(ToLower('\xff'), '\xff');
 
-    std::string testVector;
-    Downcase(testVector);
-    BOOST_CHECK_EQUAL(testVector, "");
-
-    testVector = "#HODL";
-    Downcase(testVector);
-    BOOST_CHECK_EQUAL(testVector, "#hodl");
-
-    testVector = "\x00\xfe\xff";
-    Downcase(testVector);
-    BOOST_CHECK_EQUAL(testVector, "\x00\xfe\xff");
+    BOOST_CHECK_EQUAL(ToLower(""), "");
+    BOOST_CHECK_EQUAL(ToLower("#HODL"), "#hodl");
+    BOOST_CHECK_EQUAL(ToLower("\x00\xfe\xff"), "\x00\xfe\xff");
 }
 
 BOOST_AUTO_TEST_CASE(test_ToUpper)
@@ -1346,6 +1338,10 @@ BOOST_AUTO_TEST_CASE(test_ToUpper)
     BOOST_CHECK_EQUAL(ToUpper('{'), '{');
     BOOST_CHECK_EQUAL(ToUpper(0), 0);
     BOOST_CHECK_EQUAL(ToUpper('\xff'), '\xff');
+
+    BOOST_CHECK_EQUAL(ToUpper(""), "");
+    BOOST_CHECK_EQUAL(ToUpper("#hodl"), "#HODL");
+    BOOST_CHECK_EQUAL(ToUpper("\x00\xfe\xff"), "\x00\xfe\xff");
 }
 
 BOOST_AUTO_TEST_CASE(test_Capitalize)
diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
index 6f05602fd7..cfb09e78eb 100644
--- a/src/util/strencodings.cpp
+++ b/src/util/strencodings.cpp
@@ -630,9 +630,18 @@ std::string HexStr(const Span<const uint8_t> s)
     return rv;
 }
 
-void Downcase(std::string& str)
+std::string ToLower(const std::string& str)
 {
-    std::transform(str.begin(), str.end(), str.begin(), [](char c){return ToLower(c);});
+    std::string r;
+    for (auto ch : str) r += ToLower((unsigned char)ch);
+    return r;
+}
+
+std::string ToUpper(const std::string& str)
+{
+    std::string r;
+    for (auto ch : str) r += ToUpper((unsigned char)ch);
+    return r;
 }
 
 std::string Capitalize(std::string str)
diff --git a/src/util/strencodings.h b/src/util/strencodings.h
index 79a5937713..54e4777fb5 100644
--- a/src/util/strencodings.h
+++ b/src/util/strencodings.h
@@ -203,6 +203,8 @@ bool ConvertBits(const O& outfn, I it, I end) {
  * Converts the given character to its lowercase equivalent.
  * This function is locale independent. It only converts uppercase
  * characters in the standard 7-bit ASCII range.
+ * This is a feature, not a limitation.
+ *
  * @param[in] c     the character to convert to lowercase.
  * @return          the lowercase equivalent of c; or the argument
  *                  if no conversion is possible.
@@ -213,17 +215,22 @@ constexpr char ToLower(char c)
 }
 
 /**
- * Converts the given string to its lowercase equivalent.
+ * Returns the lowercase equivalent of the given string.
  * This function is locale independent. It only converts uppercase
  * characters in the standard 7-bit ASCII range.
- * @param[in,out] str   the string to convert to lowercase.
+ * This is a feature, not a limitation.
+ *
+ * @param[in] str   the string to convert to lowercase.
+ * @returns         lowercased equivalent of str
  */
-void Downcase(std::string& str);
+std::string ToLower(const std::string& str);
 
 /**
  * Converts the given character to its uppercase equivalent.
  * This function is locale independent. It only converts lowercase
  * characters in the standard 7-bit ASCII range.
+ * This is a feature, not a limitation.
+ *
  * @param[in] c     the character to convert to uppercase.
  * @return          the uppercase equivalent of c; or the argument
  *                  if no conversion is possible.
@@ -233,13 +240,25 @@ constexpr char ToUpper(char c)
     return (c >= 'a' && c <= 'z' ? (c - 'a') + 'A' : c);
 }
 
+/**
+ * Returns the uppercase equivalent of the given string.
+ * This function is locale independent. It only converts lowercase
+ * characters in the standard 7-bit ASCII range.
+ * This is a feature, not a limitation.
+ *
+ * @param[in] str   the string to convert to uppercase.
+ * @returns         UPPERCASED EQUIVALENT OF str
+ */
+std::string ToUpper(const std::string& str);
+
 /**
  * Capitalizes the first character of the given string.
- * This function is locale independent. It only capitalizes the
- * first character of the argument if it has an uppercase equivalent
- * in the standard 7-bit ASCII range.
+ * This function is locale independent. It only converts lowercase
+ * characters in the standard 7-bit ASCII range.
+ * This is a feature, not a limitation.
+ *
  * @param[in] str   the string to capitalize.
- * @return          string with the first letter capitalized.
+ * @returns         string with the first letter capitalized.
  */
 std::string Capitalize(std::string str);
 
diff --git a/src/util/system.cpp b/src/util/system.cpp
index e08f0a2256..015220eed5 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -427,7 +427,7 @@ bool ArgsManager::ParseParameters(int argc, const char* const argv[], std::strin
             key.erase(is_index);
         }
 #ifdef WIN32
-        std::transform(key.begin(), key.end(), key.begin(), ToLower);
+        key = ToLower(key);
         if (key[0] == '/')
             key[0] = '-';
 #endif