diff --git a/CMakeLists.txt b/CMakeLists.txt
index 798e022f..2567ec26 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -82,8 +82,8 @@ enable_testing()
 
 include_directories(.)
 
-add_library(test-main
-  test/test-main.cc test/gtest-extra.cc test/gtest-extra.h)
+set(TEST_MAIN_SRC test/test-main.cc test/gtest-extra.cc test/gtest-extra.h)
+add_library(test-main ${TEST_MAIN_SRC})
 target_link_libraries(test-main gtest format)
 
 cxx_test(gtest-extra-test test-main)
@@ -96,6 +96,14 @@ if (HAVE_STD_CPP11_FLAG)
   set_target_properties(format-test PROPERTIES COMPILE_FLAGS "-std=c++11")
 endif ()
 
+if (HAVE_OPEN)
+  add_executable(posix-test test/posix-test.cc ${TEST_MAIN_SRC})
+  set_target_properties(posix-test
+    PROPERTIES COMPILE_DEFINITIONS "FMT_INCLUDE_POSIX_TEST=1")
+  target_link_libraries(posix-test gtest format)
+  add_test(posix-test posix-test)
+endif ()
+
 add_test(compile-test ${CMAKE_CTEST_COMMAND}
   --build-and-test
   "${CMAKE_CURRENT_SOURCE_DIR}/test"
diff --git a/test/gtest-extra-test.cc b/test/gtest-extra-test.cc
index 81af62bd..dfa13364 100644
--- a/test/gtest-extra-test.cc
+++ b/test/gtest-extra-test.cc
@@ -348,6 +348,12 @@ TEST(StreamingAssertionsTest, EXPECT_WRITE) {
       << "expected failure", "expected failure");
 }
 
+TEST(UtilTest, FormatSystemErrorMessage) {
+  fmt::Writer out;
+  fmt::internal::FormatSystemErrorMessage(out, EDOM, "test message");
+  EXPECT_EQ(out.str(), FormatSystemErrorMessage(EDOM, "test message"));
+}
+
 #if FMT_USE_FILE_DESCRIPTORS
 
 // Checks if the file is open by reading one character from it.
@@ -800,8 +806,6 @@ TEST(OutputRedirectTest, ErrorInDtor) {
   write_copy.dup2(write_fd); // "undo" close or dtor of BufferedFile will fail
 }
 
-// TODO: test retry on EINTR, test FormatSystemErrorMessage
-
 #endif  // FMT_USE_FILE_DESCRIPTORS
 
 }  // namespace
diff --git a/test/gtest-extra.cc b/test/gtest-extra.cc
index 5eec3607..5486aef7 100644
--- a/test/gtest-extra.cc
+++ b/test/gtest-extra.cc
@@ -46,6 +46,10 @@
 
 #endif  // _WIN32
 
+#ifdef FMT_INCLUDE_POSIX_TEST
+# include "posix-test.h"
+#endif
+
 // Retries the expression while it evaluates to -1 and error equals to EINTR.
 #define FMT_RETRY(result, expression) \
   do { \
@@ -53,7 +57,6 @@
   } while (result == -1 && errno == EINTR)
 
 namespace {
-// TODO: test
 #ifdef _WIN32
 // On Windows the count argument to read and write is unsigned, so convert
 // it from size_t preventing integer overflow.
diff --git a/test/posix-test.cc b/test/posix-test.cc
new file mode 100644
index 00000000..e714d987
--- /dev/null
+++ b/test/posix-test.cc
@@ -0,0 +1,69 @@
+/*
+ Test wrappers around POSIX functions.
+
+ Copyright (c) 2012-2014, Victor Zverovich
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+    list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "posix-test.h"
+
+#undef open
+
+#include <errno.h>
+#include <fcntl.h>
+
+#include "gtest-extra.h"
+
+namespace {
+int open_count;
+}
+
+#ifndef _WIN32
+int test::open(const char *path, int oflag, int mode) {
+  if ((open_count++ % 3) == 2)
+    return ::open(path, oflag, mode);
+  errno = EINTR;
+  return -1;
+}
+#else
+errno_t test::sopen_s(int* pfh, const char *filename, int oflag, int shflag, int pmode) {
+  return _sopen_s(pfh, filename, oflag, shflag, pmode);
+}
+#endif
+
+#ifndef _WIN32
+# define EXPECT_RETRY(statement, func, message) \
+    func##_count = 0; \
+    statement; \
+    EXPECT_EQ(3, func##_count);
+#else
+# define EXPECT_RETRY(statement, func, message) \
+    EXPECT_SYSTEM_ERROR(statement, EINTR, message);
+#endif
+
+TEST(FileTest, OpenRetry) {
+  EXPECT_RETRY(File file("CMakeLists.txt", File::RDONLY),
+               open, "cannot open file CMakeLists.txt");
+}
+
+// TODO: test retry on EINTR
diff --git a/test/posix-test.h b/test/posix-test.h
new file mode 100644
index 00000000..89924f95
--- /dev/null
+++ b/test/posix-test.h
@@ -0,0 +1,45 @@
+/*
+ Test wrappers around POSIX functions.
+
+ Copyright (c) 2012-2014, Victor Zverovich
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice, this
+    list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef FMT_POSIX_TEST_H
+#define FMT_POSIX_TEST_H
+
+#include <errno.h>
+
+namespace test {
+
+#ifndef _WIN32
+int open(const char *path, int oflag, int mode);
+#define open test::open
+#else
+errno_t sopen_s(int* pfh, const char *filename, int oflag, int shflag, int pmode);
+#define _sopen_s test::sopen_s
+#endif
+
+}  // namespace test
+
+#endif  // FMT_POSIX_TEST_H