diff --git a/generator/maxspeeds_parser.cpp b/generator/maxspeeds_parser.cpp
index 072777117..94a9ae3a0 100644
--- a/generator/maxspeeds_parser.cpp
+++ b/generator/maxspeeds_parser.cpp
@@ -173,7 +173,7 @@ bool ParseMaxspeedTag(std::string const & maxspeedValue, routing::SpeedInUnits &
     speedStr += maxspeedValue[i];
   }
 
-  while (i < maxspeedValue.size() && isspace(maxspeedValue[i]))
+  while (i < maxspeedValue.size() && strings::IsASCIISpace(maxspeedValue[i]))
     ++i;
 
   if (maxspeedValue.size() == i || maxspeedValue.substr(i).starts_with("kmh"))
diff --git a/libs/base/string_utils.cpp b/libs/base/string_utils.cpp
index b6369f034..24ccc63a1 100644
--- a/libs/base/string_utils.cpp
+++ b/libs/base/string_utils.cpp
@@ -11,6 +11,7 @@
 
 #include <fast_double_parser.h>
 #include <boost/algorithm/string/trim.hpp>
+#include <string>
 
 namespace strings
 {
@@ -227,15 +228,15 @@ void AsciiToUpper(std::string & s)
 
 void Trim(std::string & s)
 {
-  boost::trim_if(s, ::isspace);
+  boost::trim_if(s, IsASCIISpace<std::string::value_type>);
 }
 
 void Trim(std::string_view & sv)
 {
-  auto const beg = std::find_if(sv.cbegin(), sv.cend(), [](auto c) { return !std::isspace(c); });
+  auto const beg = std::find_if(sv.cbegin(), sv.cend(), [](auto c) { return !IsASCIISpace(c); });
   if (beg != sv.end())
   {
-    auto const end = std::find_if(sv.crbegin(), sv.crend(), [](auto c) { return !std::isspace(c); }).base();
+    auto const end = std::find_if(sv.crbegin(), sv.crend(), [](auto c) { return !IsASCIISpace(c); }).base();
     sv = std::string_view(sv.data() + std::distance(sv.begin(), beg), std::distance(beg, end));
   }
   else
@@ -355,11 +356,6 @@ bool IsASCIIDigit(UniChar c)
   return c >= '0' && c <= '9';
 }
 
-bool IsASCIISpace(UniChar c)
-{
-  return c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v';
-}
-
 bool IsASCIILatin(UniChar c)
 {
   return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
diff --git a/libs/base/string_utils.hpp b/libs/base/string_utils.hpp
index 6bb77b17d..3bcd603f5 100644
--- a/libs/base/string_utils.hpp
+++ b/libs/base/string_utils.hpp
@@ -105,9 +105,7 @@ size_t CountNormLowerSymbols(UniString const & s, UniString const & lowStr);
 void AsciiToLower(std::string & s);
 void AsciiToUpper(std::string & s);
 
-// All triming functions return a reference on an input string.
-// They do in-place trimming. In general, it does not work for any unicode whitespace except
-// ASCII U+0020 one.
+// All trimming functions do in-place trimming. Only ASCII whitespaces are trimmed.
 void Trim(std::string & s);
 void Trim(std::string_view & sv);
 /// Remove any characters that contain in "anyOf" on left and right side of string s
@@ -156,7 +154,23 @@ inline bool IsASCIINumeric(char const * s)
 {
   return IsASCIINumeric(std::string_view(s));
 }
-bool IsASCIISpace(UniChar c);
+
+// std::isspace is locale-dependent and fails for trailing UTF-8 characters.
+template <std::integral T>
+inline constexpr bool IsASCIISpace(T c)
+{
+  switch (c)
+  {
+  case ' ':
+  case '\f':
+  case '\n':
+  case '\r':
+  case '\t':
+  case '\v': return true;
+  default: return false;
+  }
+}
+
 bool IsASCIILatin(UniChar c);
 
 inline std::string DebugPrint(UniString const & s)
diff --git a/libs/indexer/road_shields_parser.cpp b/libs/indexer/road_shields_parser.cpp
index 660fd10d2..d9a7e2d9d 100644
--- a/libs/indexer/road_shields_parser.cpp
+++ b/libs/indexer/road_shields_parser.cpp
@@ -240,7 +240,7 @@ public:
   {
     std::string shieldText(rawText);
 
-    std::erase_if(shieldText, [](char c) { return c == '-' || ::isspace(c); });
+    std::erase_if(shieldText, [](char c) { return c == '-' || strings::IsASCIISpace(c); });
 
     if (shieldText.size() <= 2)
       return RoadShield(RoadShieldType::Default, rawText);
diff --git a/libs/platform/measurement_utils.cpp b/libs/platform/measurement_utils.cpp
index 25f155259..94000e157 100644
--- a/libs/platform/measurement_utils.cpp
+++ b/libs/platform/measurement_utils.cpp
@@ -279,7 +279,7 @@ bool OSMDistanceToMeters(std::string const & osmRawValue, double & outMeters)
   case ';': return false;
   }
 
-  while (*stop && isspace(*stop))
+  while (*stop && strings::IsASCIISpace(*stop))
     ++stop;
 
   // Default units - meters.
diff --git a/libs/routing/turns.cpp b/libs/routing/turns.cpp
index 012512555..21b82a0ab 100644
--- a/libs/routing/turns.cpp
+++ b/libs/routing/turns.cpp
@@ -11,6 +11,7 @@
 #include <algorithm>
 #include <array>
 #include <sstream>
+#include <string>
 #include <utility>
 
 namespace routing
@@ -312,7 +313,7 @@ bool ParseLanes(string lanesString, vector<SingleLaneInfo> & lanes)
     return false;
   lanes.clear();
   strings::AsciiToLower(lanesString);
-  base::EraseIf(lanesString, [](char c) { return isspace(c); });
+  base::EraseIf(lanesString, strings::IsASCIISpace<std::string::value_type>);
 
   vector<string> SplitLanesStrings;
   SingleLaneInfo lane;
diff --git a/libs/search/processor.cpp b/libs/search/processor.cpp
index b8665219d..b0273f097 100644
--- a/libs/search/processor.cpp
+++ b/libs/search/processor.cpp
@@ -86,7 +86,7 @@ void RemoveStopWordsIfNeeded(QueryTokens & tokens, strings::UniString & prefix)
 
 void TrimLeadingSpaces(string & s)
 {
-  while (!s.empty() && isspace(s.front()))
+  while (!s.empty() && strings::IsASCIISpace(s.front()))
     s = s.substr(1);
 }