diff --git a/src/common/unicode.cpp b/src/common/unicode.cpp
index 5ee37122..3d107f46 100644
--- a/src/common/unicode.cpp
+++ b/src/common/unicode.cpp
@@ -35,7 +35,7 @@
 // Static
 //
 // TODO This list should be derived from the Unicode database.
-bool unicodeWhitespace (int c)
+bool unicodeWhitespace (unsigned int c)
 {
   return (c == 0x0020 ||   // space Common  Separator, space
           c == 0x0009 ||   // Common  Other, control  HT, Horizontal Tab
diff --git a/test/.gitignore b/test/.gitignore
index 0b562dd4..0b2c1586 100644
--- a/test/.gitignore
+++ b/test/.gitignore
@@ -10,4 +10,5 @@ rules.t
 rx.t
 table.t
 text.t
+unicode.t
 utf8.t
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 575b2fb2..cd63896e 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -9,7 +9,7 @@ include_directories (${CMAKE_SOURCE_DIR}
                      ${CMAKE_SOURCE_DIR}/test
                      ${TIMEW_INCLUDE_DIRS})
 
-set (test_SRCS color.t fs.t grammar.t lexer.t list.t lr0.t pig.t rules.t rx.t table.t text.t utf8.t)
+set (test_SRCS color.t fs.t grammar.t lexer.t list.t lr0.t pig.t rules.t rx.t table.t text.t unicode.t utf8.t)
 
 add_custom_target (test ./run_all --verbose
                         DEPENDS ${test_SRCS} timew_executable
diff --git a/test/unicode.t.cpp b/test/unicode.t.cpp
new file mode 100644
index 00000000..4b9b675d
--- /dev/null
+++ b/test/unicode.t.cpp
@@ -0,0 +1,68 @@
+////////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2013 - 2016, Göteborg Bit Factory.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+// http://www.opensource.org/licenses/mit-license.php
+//
+////////////////////////////////////////////////////////////////////////////////
+
+#include <cmake.h>
+#include <unicode.h>
+#include <test.h>
+
+////////////////////////////////////////////////////////////////////////////////
+int main (int, char**)
+{
+  UnitTest t (27);
+
+  // White space detection.
+  t.notok (unicodeWhitespace (0x0041), "U+0041 (A) ! unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x0020), "U+0020 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x0009), "U+0009 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x000A), "U+000A unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x000B), "U+000B unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x000C), "U+000C unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x000D), "U+000D unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x0085), "U+0085 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x00A0), "U+00A0 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x1680), "U+1680 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x180E), "U+180E unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2000), "U+2000 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2001), "U+2001 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2002), "U+2002 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2003), "U+2003 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2004), "U+2004 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2005), "U+2005 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2006), "U+2006 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2007), "U+2007 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2008), "U+2008 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2009), "U+2009 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x200A), "U+200A unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2028), "U+2028 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x2029), "U+2029 unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x202F), "U+202F unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x205F), "U+205F unicodeWhitespace");
+  t.ok    (unicodeWhitespace (0x3000), "U+3000 unicodeWhitespace");
+
+  return 0;
+}
+
+////////////////////////////////////////////////////////////////////////////////