diff --git a/CMakeLists.txt b/CMakeLists.txt
index cbda3ac..571da1d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -236,6 +236,12 @@ if (TIDY_RC_NUMBER)
     add_definitions ( -DRC_NUMBER="${TIDY_RC_NUMBER}" )
 endif ()
 
+# If your OS doesn't have native ISO2022 support, then build with this flag.
+if (NO_NATIVE_ISO2022_SUPPORT)
+    add_definitions ( -DNO_NATIVE_ISO2022_SUPPORT=1 )
+endif ()
+
+
 # Delete me? Not used in Tidy source!
 add_definitions ( -DHAVE_CONFIG_H ) 
 
diff --git a/src/streamio.c b/src/streamio.c
index 0acca02..00ed3ba 100644
--- a/src/streamio.c
+++ b/src/streamio.c
@@ -1193,7 +1193,7 @@ static uint ReadCharFromStream( StreamIn* in )
 
         return c;
     }
-#endif /* #ifndef NO_NATIVE_ISO2022_SUPPORT */
+#endif /* NO_NATIVE_ISO2022_SUPPORT */
 
     if ( in->encoding == UTF16LE )
     {