diff --git a/configure.ac b/configure.ac
index 499f539cebb74..7ad8aa107b0b0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1048,7 +1048,6 @@ AC_CHECK_DECLS([getifaddrs, freeifaddrs],[CHECK_SOCKET],,
     [#include <sys/types.h>
     #include <ifaddrs.h>]
 )
-AC_CHECK_DECLS([strnlen])
 
 dnl These are used for daemonization in dashd
 AC_CHECK_DECLS([fork])
diff --git a/src/Makefile.am b/src/Makefile.am
index 55ffd7a6c6905..7dfa2c60737e7 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -792,7 +792,6 @@ libbitcoin_util_a_SOURCES = \
   support/lockedpool.cpp \
   chainparamsbase.cpp \
   clientversion.cpp \
-  compat/strnlen.cpp \
   fs.cpp \
   interfaces/echo.cpp \
   interfaces/handler.cpp \
diff --git a/src/compat.h b/src/compat.h
index 41f2cd7398604..e2f784b96f083 100644
--- a/src/compat.h
+++ b/src/compat.h
@@ -81,10 +81,6 @@ typedef int32_t ssize_t;
 #endif
 #endif
 
-#if HAVE_DECL_STRNLEN == 0
-size_t strnlen( const char *start, size_t max_len);
-#endif // HAVE_DECL_STRNLEN
-
 #ifndef WIN32
 typedef void* sockopt_arg_type;
 #else
diff --git a/src/compat/strnlen.cpp b/src/compat/strnlen.cpp
deleted file mode 100644
index 72b69953d0af5..0000000000000
--- a/src/compat/strnlen.cpp
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright (c) 2009-2014 The Bitcoin Core developers
-// Distributed under the MIT software license, see the accompanying
-// file COPYING or http://www.opensource.org/licenses/mit-license.php.
-
-#if defined(HAVE_CONFIG_H)
-#include <config/bitcoin-config.h>
-#endif
-
-#include <cstring>
-
-#if HAVE_DECL_STRNLEN == 0
-size_t strnlen( const char *start, size_t max_len)
-{
-    const char *end = (const char *)memchr(start, '\0', max_len);
-
-    return end ? (size_t)(end - start) : max_len;
-}
-#endif // HAVE_DECL_STRNLEN
\ No newline at end of file