diff --git a/src/base58.cpp b/src/base58.cpp
index 306547ce1e..849293634a 100644
--- a/src/base58.cpp
+++ b/src/base58.cpp
@@ -36,7 +36,7 @@ static const int8_t mapBase58[256] = {
 bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
 {
     // Skip leading spaces.
-    while (*psz && isspace(*psz))
+    while (*psz && IsSpace(*psz))
         psz++;
     // Skip and count leading '1's.
     int zeroes = 0;
@@ -50,7 +50,7 @@ bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
     std::vector<unsigned char> b256(size);
     // Process the characters.
     static_assert(sizeof(mapBase58)/sizeof(mapBase58[0]) == 256, "mapBase58.size() should be 256"); // guarantee not out of range
-    while (*psz && !isspace(*psz)) {
+    while (*psz && !IsSpace(*psz)) {
         // Decode base58 character
         int carry = mapBase58[(uint8_t)*psz];
         if (carry == -1)  // Invalid b58 character
@@ -66,7 +66,7 @@ bool DecodeBase58(const char* psz, std::vector<unsigned char>& vch)
         psz++;
     }
     // Skip trailing spaces.
-    while (isspace(*psz))
+    while (IsSpace(*psz))
         psz++;
     if (*psz != 0)
         return false;
diff --git a/src/governance/governance-validators.cpp b/src/governance/governance-validators.cpp
index 379771d59c..1e1936a1fc 100644
--- a/src/governance/governance-validators.cpp
+++ b/src/governance/governance-validators.cpp
@@ -100,7 +100,7 @@ bool CProposalValidator::ValidateName()
 
     static const std::string strAllowedChars = "-_abcdefghijklmnopqrstuvwxyz0123456789";
 
-    std::transform(strName.begin(), strName.end(), strName.begin(), ::tolower);
+    std::transform(strName.begin(), strName.end(), strName.begin(), ToLower);
 
     if (strName.find_first_not_of(strAllowedChars) != std::string::npos) {
         strErrorMessages += "name contains invalid characters;";
@@ -168,7 +168,7 @@ bool CProposalValidator::ValidatePaymentAddress()
         return false;
     }
 
-    if (std::find_if(strPaymentAddress.begin(), strPaymentAddress.end(), ::isspace) != strPaymentAddress.end()) {
+    if (std::find_if(strPaymentAddress.begin(), strPaymentAddress.end(), IsSpace) != strPaymentAddress.end()) {
         strErrorMessages += "payment_address can't have whitespaces;";
         return false;
     }
@@ -196,7 +196,7 @@ bool CProposalValidator::ValidateURL()
         return false;
     }
 
-    if (std::find_if(strURL.begin(), strURL.end(), ::isspace) != strURL.end()) {
+    if (std::find_if(strURL.begin(), strURL.end(), IsSpace) != strURL.end()) {
         strErrorMessages += "url can't have whitespaces;";
         return false;
     }
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index 54f0fe8665..708c4f0e56 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -20,6 +20,7 @@
 #include <netbase.h>
 #include <rpc/server.h>
 #include <rpc/client.h>
+#include <util/strencodings.h>
 #include <util/system.h>
 
 #include <openssl/crypto.h>
@@ -229,7 +230,7 @@ bool RPCConsole::RPCParseCommandLine(interfaces::Node* node, std::string &strRes
                                 if (lastResult.isArray())
                                 {
                                     for(char argch: curarg)
-                                        if (!std::isdigit(argch))
+                                        if (!IsDigit(argch))
                                             throw std::runtime_error("Invalid result query");
                                     subelement = lastResult[atoi(curarg.c_str())];
                                 }
diff --git a/src/rpc/masternode.cpp b/src/rpc/masternode.cpp
index bf3c6882b6..4b18dabe33 100644
--- a/src/rpc/masternode.cpp
+++ b/src/rpc/masternode.cpp
@@ -557,7 +557,7 @@ 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);
+    std::transform(strMode.begin(), strMode.end(), strMode.begin(), ToLower);
 
     if (request.fHelp || (
                 strMode != "addr" && strMode != "full" && strMode != "info" && strMode != "json" &&
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
index 6ac222c0f5..1be07ef686 100644
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -187,7 +187,7 @@ 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);
+    std::transform(strBool.begin(), strBool.end(), strBool.begin(), ToLower);
 
     if (strBool == "true" || strBool == "yes" || strBool == "1") {
         return true;
diff --git a/src/test/getarg_tests.cpp b/src/test/getarg_tests.cpp
index f3ad0fe94b..311956bb5f 100644
--- a/src/test/getarg_tests.cpp
+++ b/src/test/getarg_tests.cpp
@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <util/strencodings.h>
 #include <util/system.h>
 #include <test/test_dash.h>
 
@@ -17,7 +18,7 @@ static void ResetArgs(const std::string& strArg)
 {
     std::vector<std::string> vecArg;
     if (strArg.size())
-      boost::split(vecArg, strArg, boost::is_space(), boost::token_compress_on);
+      boost::split(vecArg, strArg, IsSpace, boost::token_compress_on);
 
     // Insert dummy executable name:
     vecArg.insert(vecArg.begin(), "testdash");
diff --git a/src/uint256.cpp b/src/uint256.cpp
index dfd9218b86..2872901a65 100644
--- a/src/uint256.cpp
+++ b/src/uint256.cpp
@@ -33,11 +33,11 @@ void base_blob<BITS>::SetHex(const char* psz)
     memset(m_data, 0, sizeof(m_data));
 
     // skip leading spaces
-    while (isspace(*psz))
+    while (IsSpace(*psz))
         psz++;
 
     // skip 0x
-    if (psz[0] == '0' && tolower(psz[1]) == 'x')
+    if (psz[0] == '0' && ToLower((unsigned char)psz[1]) == 'x')
         psz += 2;
 
     // hex string to uint
diff --git a/src/util/moneystr.cpp b/src/util/moneystr.cpp
index bc376f1dc1..5d2f372d23 100644
--- a/src/util/moneystr.cpp
+++ b/src/util/moneystr.cpp
@@ -20,7 +20,7 @@ std::string FormatMoney(const CAmount& n)
 
     // Right-trim excess zeros before the decimal point:
     int nTrim = 0;
-    for (int i = str.size()-1; (str[i] == '0' && isdigit(str[i-2])); --i)
+    for (int i = str.size()-1; (str[i] == '0' && IsDigit(str[i-2])); --i)
         ++nTrim;
     if (nTrim)
         str.erase(str.size()-nTrim, nTrim);
@@ -41,7 +41,7 @@ bool ParseMoney(const char* pszIn, CAmount& nRet)
     std::string strWhole;
     int64_t nUnits = 0;
     const char* p = pszIn;
-    while (isspace(*p))
+    while (IsSpace(*p))
         p++;
     for (; *p; p++)
     {
@@ -49,21 +49,21 @@ bool ParseMoney(const char* pszIn, CAmount& nRet)
         {
             p++;
             int64_t nMult = COIN / 10;
-            while (isdigit(*p) && (nMult > 0))
+            while (IsDigit(*p) && (nMult > 0))
             {
                 nUnits += nMult * (*p++ - '0');
                 nMult /= 10;
             }
             break;
         }
-        if (isspace(*p))
+        if (IsSpace(*p))
             break;
-        if (!isdigit(*p))
+        if (!IsDigit(*p))
             return false;
         strWhole.insert(strWhole.end(), *p);
     }
     for (; *p; p++)
-        if (!isspace(*p))
+        if (!IsSpace(*p))
             return false;
     if (strWhole.size() > 10) // guard against 63 bit overflow
         return false;
diff --git a/src/util/strencodings.cpp b/src/util/strencodings.cpp
index 27d757ef46..9481ca4573 100644
--- a/src/util/strencodings.cpp
+++ b/src/util/strencodings.cpp
@@ -87,7 +87,7 @@ std::vector<unsigned char> ParseHex(const char* psz)
     std::vector<unsigned char> vch;
     while (true)
     {
-        while (isspace(*psz))
+        while (IsSpace(*psz))
             psz++;
         signed char c = HexDigit(*psz++);
         if (c == (signed char)-1)
@@ -272,7 +272,7 @@ std::string DecodeBase32(const std::string& str, bool* pf_invalid)
 {
     if (str.empty()) // No empty string allowed
         return false;
-    if (str.size() >= 1 && (isspace(str[0]) || isspace(str[str.size()-1]))) // No padding allowed
+    if (str.size() >= 1 && (IsSpace(str[0]) || IsSpace(str[str.size()-1]))) // No padding allowed
         return false;
     if (!ValidAsCString(str)) // No embedded NUL characters allowed
         return false;
diff --git a/src/util/strencodings.h b/src/util/strencodings.h
index f4a359854f..79a5937713 100644
--- a/src/util/strencodings.h
+++ b/src/util/strencodings.h
@@ -84,6 +84,21 @@ constexpr bool IsDigit(char c)
     return c >= '0' && c <= '9';
 }
 
+/**
+ * Tests if the given character is a whitespace character. The whitespace characters
+ * are: space, form-feed ('\f'), newline ('\n'), carriage return ('\r'), horizontal
+ * tab ('\t'), and vertical tab ('\v').
+ *
+ * This function is locale independent. Under the C locale this function gives the
+ * same result as std::isspace.
+ *
+ * @param[in] c     character to test
+ * @return          true if the argument is a whitespace character; otherwise false
+ */
+constexpr inline bool IsSpace(char c) noexcept {
+    return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v';
+}
+
 /**
  * Convert string to signed 32-bit integer with strict parse error feedback.
  * @returns true if the entire string could be parsed as valid integer,
diff --git a/src/util/system.cpp b/src/util/system.cpp
index df605a6046..42f6cdc353 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -458,7 +458,7 @@ 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);
+        std::transform(key.begin(), key.end(), key.begin(), ToLower);
         if (key[0] == '/')
             key[0] = '-';
 #endif
diff --git a/test/lint/lint-locale-dependence.sh b/test/lint/lint-locale-dependence.sh
index cd6e93eb32..79f5b2bb82 100755
--- a/test/lint/lint-locale-dependence.sh
+++ b/test/lint/lint-locale-dependence.sh
@@ -3,46 +3,30 @@
 export LC_ALL=C
 
 KNOWN_VIOLATIONS=(
-    "src/base58.cpp:.*isspace"
     "src/bench/string_cast.cpp.*atoi"
     "src/dash-tx.cpp.*stoul"
     "src/dash-tx.cpp.*trim_right"
-    "src/dash-tx.cpp:.*atoi"
-    "src/core_read.cpp.*is_digit"
     "src/dbwrapper.cpp.*stoul"
     "src/dbwrapper.cpp:.*vsnprintf"
-    "src/governance/governance-validators.cpp.*isspace"
-    "src/governance/governance-validators.cpp.*tolower"
     "src/httprpc.cpp.*trim"
     "src/init.cpp:.*atoi"
     "src/init.cpp:.*fprintf"
     "src/qt/rpcconsole.cpp:.*atoi"
-    "src/qt/rpcconsole.cpp:.*isdigit"
     "src/rest.cpp:.*strtol"
     "src/rpc/blockchain.cpp.*atoi"
     "src/rpc/governance.cpp.*atoi"
     "src/rpc/masternode.cpp.*atoi"
-    "src/rpc/masternode.cpp.*tolower"
-    "src/rpc/server.cpp.*tolower"
     "src/statsd_client.cpp:.*snprintf"
     "src/test/dbwrapper_tests.cpp:.*snprintf"
-    "src/test/getarg_tests.cpp.*split"
     "src/torcontrol.cpp:.*atoi"
     "src/torcontrol.cpp:.*strtol"
-    "src/uint256.cpp:.*isspace"
-    "src/uint256.cpp:.*tolower"
-    "src/util/system.cpp:.*atoi"
-    "src/util/system.cpp:.*tolower"
-    "src/util/moneystr.cpp:.*isdigit"
-    "src/util/moneystr.cpp:.*isspace"
     "src/util/strencodings.cpp:.*atoi"
-    "src/util/strencodings.cpp:.*isspace"
     "src/util/strencodings.cpp:.*strtol"
-    "src/util/strencodings.cpp:.*strtoll"
     "src/util/strencodings.cpp:.*strtoul"
-    "src/util/strencodings.cpp:.*strtoull"
     "src/util/strencodings.h:.*atoi"
     "src/wallet/wallet.cpp:.*atoi"
+    "src/util/system.cpp:.*atoi"
+    "src/util/system.cpp:.*fprintf"
 )
 
 REGEXP_IGNORE_EXTERNAL_DEPENDENCIES="^src/(crypto/ctaes/|leveldb/|secp256k1/|tinyformat.h|univalue/)"