diff --git a/scintilla/boostregex/AnsiDocumentIterator.h b/scintilla/boostregex/AnsiDocumentIterator.h
index 4e469800..b4e0e368 100644
--- a/scintilla/boostregex/AnsiDocumentIterator.h
+++ b/scintilla/boostregex/AnsiDocumentIterator.h
@@ -1,6 +1,10 @@
 #ifndef ANSIDOCUMENTITERATOR_H_12481491281240
 #define ANSIDOCUMENTITERATOR_H_12481491281240
 
+#ifdef SCI_NAMESPACE
+namespace Scintilla {
+#endif
+
 class AnsiDocumentIterator : public std::iterator<std::bidirectional_iterator_tag, char>
 {
 public:
@@ -91,4 +95,8 @@ private:
 	Document* m_doc;
 };
 
+#ifdef SCI_NAMESPACE
+}
+#endif
+
 #endif
\ No newline at end of file
diff --git a/scintilla/boostregex/UTF8DocumentIterator.cxx b/scintilla/boostregex/UTF8DocumentIterator.cxx
index e075c4f3..ab995314 100644
--- a/scintilla/boostregex/UTF8DocumentIterator.cxx
+++ b/scintilla/boostregex/UTF8DocumentIterator.cxx
@@ -1,5 +1,8 @@
 #include "UTF8DocumentIterator.h"
 
+#ifdef SCI_NAMESPACE
+using namespace Scintilla;
+#endif
 
 void UTF8DocumentIterator::readCharacter()
 {
diff --git a/scintilla/boostregex/UTF8DocumentIterator.h b/scintilla/boostregex/UTF8DocumentIterator.h
index fee1b6b4..c8522038 100644
--- a/scintilla/boostregex/UTF8DocumentIterator.h
+++ b/scintilla/boostregex/UTF8DocumentIterator.h
@@ -15,6 +15,12 @@
 #include "CaseFolder.h"
 #include <Document.h>
 
+
+#ifdef SCI_NAMESPACE
+namespace Scintilla {
+#endif
+
+
 class UTF8DocumentIterator : public std::iterator<std::bidirectional_iterator_tag, wchar_t>
 {
 public:
@@ -153,4 +159,8 @@ private:
 		static const unsigned char m_firstByteMask[];
 };
 
+#ifdef SCI_NAMESPACE
+}
+#endif
+
 #endif // UTF8DOCUMENTITERATOR_H_3452843291318441149
diff --git a/scintilla/lexers/LexObjC.cxx b/scintilla/lexers/LexObjC.cxx
index 72f70586..bfa57d5a 100644
--- a/scintilla/lexers/LexObjC.cxx
+++ b/scintilla/lexers/LexObjC.cxx
@@ -27,6 +27,10 @@
 #include "Scintilla.h"
 #include "SciLexer.h"
 
+#ifdef SCI_NAMESPACE
+using namespace Scintilla;
+#endif
+
 #define KEYWORD_BOXHEADER 1
 #define KEYWORD_FOLDCONTRACTED 2
 
diff --git a/scintilla/lexers/LexSearchResult.cxx b/scintilla/lexers/LexSearchResult.cxx
index cfb76608..ffb15f8d 100644
--- a/scintilla/lexers/LexSearchResult.cxx
+++ b/scintilla/lexers/LexSearchResult.cxx
@@ -39,6 +39,10 @@
 #include "CharacterSet.h"
 #include "LexerModule.h"
 
+#ifdef SCI_NAMESPACE
+using namespace Scintilla;
+#endif
+
 // The following definitions are a copy of the ones in FindReplaceDlg.h
 enum { searchHeaderLevel = SC_FOLDLEVELBASE + 1, fileHeaderLevel, resultLevel };
 
diff --git a/scintilla/win32/SciLexer.vcxproj b/scintilla/win32/SciLexer.vcxproj
index f7f70579..05f24192 100644
--- a/scintilla/win32/SciLexer.vcxproj
+++ b/scintilla/win32/SciLexer.vcxproj
@@ -57,7 +57,7 @@
   <ItemDefinitionGroup>
     <ClCompile>
       <WarningLevel>Level4</WarningLevel>
-      <PreprocessorDefinitions>WIN32;SCI_LEXER;_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES;_CRT_SECURE_NO_DEPRECATE;_WINDOWS;_USRDLL;SCI_OWNREGEX;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <PreprocessorDefinitions>WIN32;SCI_LEXER;_CRT_SECURE_CPP_OVERLOAD_STANDARD_NAMES;_CRT_SECURE_NO_DEPRECATE;_WINDOWS;_USRDLL;SCI_OWNREGEX;SCI_NAMESPACE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <AdditionalIncludeDirectories>..\include;..\src;..\lexlib;</AdditionalIncludeDirectories>
       <BrowseInformation>true</BrowseInformation>
       <MultiProcessorCompilation>true</MultiProcessorCompilation>
diff --git a/scintilla/win32/scintilla.mak b/scintilla/win32/scintilla.mak
index d9b5da58..d2371bde 100644
--- a/scintilla/win32/scintilla.mak
+++ b/scintilla/win32/scintilla.mak
@@ -51,6 +51,9 @@ LDFLAGS=$(LDDEBUG) $(LDFLAGS)
 CXXFLAGS=$(CXXFLAGS) $(CXXNDEBUG)
 !ENDIF
 
+#unconditionally use scintilla namespace
+CXXFLAGS=$(CXXFLAGS) -DSCI_NAMESPACE
+
 INCLUDEDIRS=-I../include -I../src -I../lexlib
 CXXFLAGS=$(CXXFLAGS) $(INCLUDEDIRS)