diff --git a/adb/Android.mk b/adb/Android.mk
index abe651d..16ed991 100644
--- a/adb/Android.mk
+++ b/adb/Android.mk
@@ -89,10 +89,12 @@
 
 LIBADB_windows_SRC_FILES := \
     sysdeps_win32.cpp \
+    sysdeps/win32/errno.cpp \
     sysdeps/win32/stat.cpp \
     usb_windows.cpp \
 
 LIBADB_TEST_windows_SRCS := \
+    sysdeps/win32/errno_test.cpp \
     sysdeps_win32_test.cpp \
 
 include $(CLEAR_VARS)
diff --git a/adb/file_sync_client.cpp b/adb/file_sync_client.cpp
index fc18393..5160569 100644
--- a/adb/file_sync_client.cpp
+++ b/adb/file_sync_client.cpp
@@ -15,12 +15,10 @@
  */
 
 #include <dirent.h>
-#include <errno.h>
 #include <inttypes.h>
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
diff --git a/adb/sysdeps.h b/adb/sysdeps.h
index 05d9fde..654072c 100644
--- a/adb/sysdeps.h
+++ b/adb/sysdeps.h
@@ -34,6 +34,7 @@
 #include <android-base/unique_fd.h>
 #include <android-base/utf8.h>
 
+#include "sysdeps/errno.h"
 #include "sysdeps/stat.h"
 
 /*
@@ -361,9 +362,6 @@
 
 #define getcwd adb_getcwd
 
-char* adb_strerror(int err);
-#define strerror adb_strerror
-
 // Helper class to convert UTF-16 argv from wmain() to UTF-8 args that can be
 // passed to main().
 class NarrowArgs {
diff --git a/adb/sysdeps/errno.h b/adb/sysdeps/errno.h
index d514184..f783b3a 100644
--- a/adb/sysdeps/errno.h
+++ b/adb/sysdeps/errno.h
@@ -16,4 +16,13 @@
 
 #pragma once
 
+#include <errno.h>
+#include <string.h>
+
+// Translate an errno value from linux to the host equivalent.
 int translate_linux_errno(int error);
+
+#if defined(_WIN32)
+char* adb_strerror(int err);
+#define strerror adb_strerror
+#endif
diff --git a/adb/sysdeps/win32/errno.cpp b/adb/sysdeps/win32/errno.cpp
new file mode 100644
index 0000000..a3b9d9b
--- /dev/null
+++ b/adb/sysdeps/win32/errno.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "sysdeps/errno.h"
+
+#include <windows.h>
+
+#include <string>
+
+// Overrides strerror() to handle error codes not supported by the Windows C
+// Runtime (MSVCRT.DLL).
+char* adb_strerror(int err) {
+// sysdeps.h defines strerror to adb_strerror, but in this function, we
+// want to call the real C Runtime strerror().
+#pragma push_macro("strerror")
+#undef strerror
+    const int saved_err = errno;  // Save because we overwrite it later.
+
+    // Lookup the string for an unknown error.
+    char* errmsg = strerror(-1);
+    const std::string unknown_error = (errmsg == nullptr) ? "" : errmsg;
+
+    // Lookup the string for this error to see if the C Runtime has it.
+    errmsg = strerror(err);
+    if (errmsg != nullptr && unknown_error != errmsg) {
+        // The CRT returned an error message and it is different than the error
+        // message for an unknown error, so it is probably valid, so use it.
+    } else {
+        // Check if we have a string for this error code.
+        const char* custom_msg = nullptr;
+        switch (err) {
+#pragma push_macro("ERR")
+#undef ERR
+#define ERR(errnum, desc) case errnum: custom_msg = desc; break
+            // These error strings are from AOSP bionic/libc/include/sys/_errdefs.h.
+            // Note that these cannot be longer than 94 characters because we
+            // pass this to _strerror() which has that requirement.
+            ERR(ECONNRESET,    "Connection reset by peer");
+            ERR(EHOSTUNREACH,  "No route to host");
+            ERR(ENETDOWN,      "Network is down");
+            ERR(ENETRESET,     "Network dropped connection because of reset");
+            ERR(ENOBUFS,       "No buffer space available");
+            ERR(ENOPROTOOPT,   "Protocol not available");
+            ERR(ENOTCONN,      "Transport endpoint is not connected");
+            ERR(ENOTSOCK,      "Socket operation on non-socket");
+            ERR(EOPNOTSUPP,    "Operation not supported on transport endpoint");
+#pragma pop_macro("ERR")
+        }
+
+        if (custom_msg != nullptr) {
+            // Use _strerror() to write our string into the writable per-thread
+            // buffer used by strerror()/_strerror(). _strerror() appends the
+            // msg for the current value of errno, so set errno to a consistent
+            // value for every call so that our code-path is always the same.
+            errno = 0;
+            errmsg = _strerror(custom_msg);
+            const size_t custom_msg_len = strlen(custom_msg);
+            // Just in case _strerror() returned a read-only string, check if
+            // the returned string starts with our custom message because that
+            // implies that the string is not read-only.
+            if ((errmsg != nullptr) && !strncmp(custom_msg, errmsg, custom_msg_len)) {
+                // _strerror() puts other text after our custom message, so
+                // remove that by terminating after our message.
+                errmsg[custom_msg_len] = '\0';
+            } else {
+                // For some reason nullptr was returned or a pointer to a
+                // read-only string was returned, so fallback to whatever
+                // strerror() can muster (probably "Unknown error" or some
+                // generic CRT error string).
+                errmsg = strerror(err);
+            }
+        } else {
+            // We don't have a custom message, so use whatever strerror(err)
+            // returned earlier.
+        }
+    }
+
+    errno = saved_err;  // restore
+
+    return errmsg;
+#pragma pop_macro("strerror")
+}
diff --git a/adb/sysdeps/win32/errno_test.cpp b/adb/sysdeps/win32/errno_test.cpp
new file mode 100644
index 0000000..09ec52c
--- /dev/null
+++ b/adb/sysdeps/win32/errno_test.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "sysdeps/errno.h"
+
+#include <string>
+
+#include <gtest/gtest.h>
+
+void TestAdbStrError(int err, const char* expected) {
+    errno = 12345;
+    const char* result = adb_strerror(err);
+    // Check that errno is not overwritten.
+    EXPECT_EQ(12345, errno);
+    EXPECT_STREQ(expected, result);
+}
+
+TEST(sysdeps_win32, adb_strerror) {
+    // Test an error code that should not have a mapped string. Use an error
+    // code that is not used by the internal implementation of adb_strerror().
+    TestAdbStrError(-2, "Unknown error");
+    // adb_strerror() uses -1 internally, so test that it can still be passed
+    // as a parameter.
+    TestAdbStrError(-1, "Unknown error");
+    // Test very big, positive unknown error.
+    TestAdbStrError(1000000, "Unknown error");
+
+    // Test success case.
+    // Wine returns "Success" for strerror(0), Windows returns "No error", so accept both.
+    std::string success = adb_strerror(0);
+    EXPECT_TRUE(success == "Success" || success == "No error") << "strerror(0) = " << success;
+
+    // Test error that regular strerror() should have a string for.
+    TestAdbStrError(EPERM, "Operation not permitted");
+    // Test error that regular strerror() doesn't have a string for, but that
+    // adb_strerror() returns.
+    TestAdbStrError(ECONNRESET, "Connection reset by peer");
+}
diff --git a/adb/sysdeps_win32.cpp b/adb/sysdeps_win32.cpp
index 4dd549d..a4b5e69 100644
--- a/adb/sysdeps_win32.cpp
+++ b/adb/sysdeps_win32.cpp
@@ -477,81 +477,6 @@
     return 0;
 }
 
-// Overrides strerror() to handle error codes not supported by the Windows C
-// Runtime (MSVCRT.DLL).
-char* adb_strerror(int err) {
-    // sysdeps.h defines strerror to adb_strerror, but in this function, we
-    // want to call the real C Runtime strerror().
-#pragma push_macro("strerror")
-#undef strerror
-    const int saved_err = errno;      // Save because we overwrite it later.
-
-    // Lookup the string for an unknown error.
-    char* errmsg = strerror(-1);
-    const std::string unknown_error = (errmsg == nullptr) ? "" : errmsg;
-
-    // Lookup the string for this error to see if the C Runtime has it.
-    errmsg = strerror(err);
-    if (errmsg != nullptr && unknown_error != errmsg) {
-        // The CRT returned an error message and it is different than the error
-        // message for an unknown error, so it is probably valid, so use it.
-    } else {
-        // Check if we have a string for this error code.
-        const char* custom_msg = nullptr;
-        switch (err) {
-#pragma push_macro("ERR")
-#undef ERR
-#define ERR(errnum, desc) case errnum: custom_msg = desc; break
-            // These error strings are from AOSP bionic/libc/include/sys/_errdefs.h.
-            // Note that these cannot be longer than 94 characters because we
-            // pass this to _strerror() which has that requirement.
-            ERR(ECONNRESET,    "Connection reset by peer");
-            ERR(EHOSTUNREACH,  "No route to host");
-            ERR(ENETDOWN,      "Network is down");
-            ERR(ENETRESET,     "Network dropped connection because of reset");
-            ERR(ENOBUFS,       "No buffer space available");
-            ERR(ENOPROTOOPT,   "Protocol not available");
-            ERR(ENOTCONN,      "Transport endpoint is not connected");
-            ERR(ENOTSOCK,      "Socket operation on non-socket");
-            ERR(EOPNOTSUPP,    "Operation not supported on transport endpoint");
-#pragma pop_macro("ERR")
-        }
-
-        if (custom_msg != nullptr) {
-            // Use _strerror() to write our string into the writable per-thread
-            // buffer used by strerror()/_strerror(). _strerror() appends the
-            // msg for the current value of errno, so set errno to a consistent
-            // value for every call so that our code-path is always the same.
-            errno = 0;
-            errmsg = _strerror(custom_msg);
-            const size_t custom_msg_len = strlen(custom_msg);
-            // Just in case _strerror() returned a read-only string, check if
-            // the returned string starts with our custom message because that
-            // implies that the string is not read-only.
-            if ((errmsg != nullptr) &&
-                !strncmp(custom_msg, errmsg, custom_msg_len)) {
-                // _strerror() puts other text after our custom message, so
-                // remove that by terminating after our message.
-                errmsg[custom_msg_len] = '\0';
-            } else {
-                // For some reason nullptr was returned or a pointer to a
-                // read-only string was returned, so fallback to whatever
-                // strerror() can muster (probably "Unknown error" or some
-                // generic CRT error string).
-                errmsg = strerror(err);
-            }
-        } else {
-            // We don't have a custom message, so use whatever strerror(err)
-            // returned earlier.
-        }
-    }
-
-    errno = saved_err;  // restore
-
-    return errmsg;
-#pragma pop_macro("strerror")
-}
-
 /**************************************************************************/
 /**************************************************************************/
 /*****                                                                *****/
@@ -565,7 +490,7 @@
 static void _socket_set_errno( const DWORD err ) {
     // Because the Windows C Runtime (MSVCRT.DLL) strerror() does not support a
     // lot of POSIX and socket error codes, some of the resulting error codes
-    // are mapped to strings by adb_strerror() above.
+    // are mapped to strings by adb_strerror().
     switch ( err ) {
     case 0:              errno = 0; break;
     // Don't map WSAEINTR since that is only for Winsock 1.1 which we don't use.
diff --git a/adb/sysdeps_win32_test.cpp b/adb/sysdeps_win32_test.cpp
index c3a3fd7..529b212 100755
--- a/adb/sysdeps_win32_test.cpp
+++ b/adb/sysdeps_win32_test.cpp
@@ -70,36 +70,6 @@
     }
 }
 
-void TestAdbStrError(int err, const char* expected) {
-    errno = 12345;
-    const char* result = adb_strerror(err);
-    // Check that errno is not overwritten.
-    EXPECT_EQ(12345, errno);
-    EXPECT_STREQ(expected, result);
-}
-
-TEST(sysdeps_win32, adb_strerror) {
-    // Test an error code that should not have a mapped string. Use an error
-    // code that is not used by the internal implementation of adb_strerror().
-    TestAdbStrError(-2, "Unknown error");
-    // adb_strerror() uses -1 internally, so test that it can still be passed
-    // as a parameter.
-    TestAdbStrError(-1, "Unknown error");
-    // Test very big, positive unknown error.
-    TestAdbStrError(1000000, "Unknown error");
-
-    // Test success case.
-    // Wine returns "Success" for strerror(0), Windows returns "No error", so accept both.
-    std::string success = adb_strerror(0);
-    EXPECT_TRUE(success == "Success" || success == "No error") << "strerror(0) = " << success;
-
-    // Test error that regular strerror() should have a string for.
-    TestAdbStrError(EPERM, "Operation not permitted");
-    // Test error that regular strerror() doesn't have a string for, but that
-    // adb_strerror() returns.
-    TestAdbStrError(ECONNRESET, "Connection reset by peer");
-}
-
 TEST(sysdeps_win32, unix_isatty) {
     // stdin and stdout should be consoles. Use CONIN$ and CONOUT$ special files
     // so that we can test this even if stdin/stdout have been redirected. Read