diff --git a/configure.ac b/configure.ac
--- a/configure.ac
+++ b/configure.ac
@@ -712,20 +712,6 @@
 AX_GCC_FUNC_ATTRIBUTE([dllimport])
 
 if test x$use_glibc_compat != xno; then
-
-  #__fdelt_chk's params and return type have changed from long unsigned int to long int.
-  # See which one is present here.
-  AC_MSG_CHECKING(__fdelt_chk type)
-  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#ifdef _FORTIFY_SOURCE
-                    #undef _FORTIFY_SOURCE
-                  #endif
-                  #define _FORTIFY_SOURCE 2
-                  #include <sys/select.h>
-     extern "C" long unsigned int __fdelt_warn(long unsigned int);]],[[]])],
-    [ fdelt_type="long unsigned int"],
-    [ fdelt_type="long int"])
-  AC_MSG_RESULT($fdelt_type)
-  AC_DEFINE_UNQUOTED(FDELT_TYPE, $fdelt_type,[parameter and return value type for __fdelt_chk])
   AX_CHECK_LINK_FLAG([[-Wl,--wrap=__divmoddi4]], [COMPAT_LDFLAGS="$COMPAT_LDFLAGS -Wl,--wrap=__divmoddi4"])
   AX_CHECK_LINK_FLAG([[-Wl,--wrap=log2f]], [COMPAT_LDFLAGS="$COMPAT_LDFLAGS -Wl,--wrap=log2f"])
   if test x$need_wrap_fcntl = xyes; then
diff --git a/src/compat/glibc_compat.cpp b/src/compat/glibc_compat.cpp
--- a/src/compat/glibc_compat.cpp
+++ b/src/compat/glibc_compat.cpp
@@ -10,24 +10,12 @@
 #include <cstddef>
 #include <cstdint>
 
-#if defined(HAVE_SYS_SELECT_H)
-#include <sys/select.h>
-#endif
-
 // Prior to GLIBC_2.14, memcpy was aliased to memmove.
 extern "C" void *memmove(void *a, const void *b, size_t c);
 extern "C" void *memcpy(void *a, const void *b, size_t c) {
     return memmove(a, b, c);
 }
 
-extern "C" void __chk_fail(void) __attribute__((__noreturn__));
-extern "C" FDELT_TYPE __fdelt_warn(FDELT_TYPE a) {
-    if (a >= FD_SETSIZE) __chk_fail();
-    return a / __NFDBITS;
-}
-extern "C" FDELT_TYPE __fdelt_chk(FDELT_TYPE)
-    __attribute__((weak, alias("__fdelt_warn")));
-
 #if defined(__i386__) || defined(__arm__)
 
 extern "C" int64_t __udivmoddi4(uint64_t u, uint64_t v, uint64_t *rp);
diff --git a/src/compat/glibc_sanity.cpp b/src/compat/glibc_sanity.cpp
--- a/src/compat/glibc_sanity.cpp
+++ b/src/compat/glibc_sanity.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2009-2014 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -8,10 +8,6 @@
 
 #include <cstddef>
 
-#if defined(HAVE_SYS_SELECT_H)
-#include <sys/select.h>
-#endif
-
 extern "C" void *memcpy(void *a, const void *b, size_t c);
 void *memcpy_int(void *a, const void *b, size_t c) {
     return memcpy(a, b, c);
@@ -39,27 +35,8 @@
     }
     return true;
 }
-
-#if defined(HAVE_SYS_SELECT_H)
-// trigger: Call FD_SET to trigger __fdelt_chk. FORTIFY_SOURCE must be defined
-//   as >0 and optimizations must be set to at least -O2.
-// test: Add a file descriptor to an empty fd_set. Verify that it has been
-//   correctly added.
-bool sanity_test_fdelt() {
-    fd_set fds;
-    FD_ZERO(&fds);
-    FD_SET(0, &fds);
-    return FD_ISSET(0, &fds);
-}
-#endif
-
 } // namespace
 
 bool glibc_sanity_test() {
-#if defined(HAVE_SYS_SELECT_H)
-    if (!sanity_test_fdelt()) {
-        return false;
-    }
-#endif
     return sanity_test_memcpy<1025>();
 }
diff --git a/src/config/CMakeLists.txt b/src/config/CMakeLists.txt
--- a/src/config/CMakeLists.txt
+++ b/src/config/CMakeLists.txt
@@ -192,20 +192,6 @@
 # and always succeed to build.
 set(CMAKE_REQUIRED_FLAGS -O2)
 
-check_prototype_definition(
-	__fdelt_warn
-	"extern long unsigned int __fdelt_warn(long unsigned int a)"
-	"0"
-	"sys/select.h"
-	FDELT_PROTOTYPE_LONG_UNSIGNED_INT
-)
-
-if(FDELT_PROTOTYPE_LONG_UNSIGNED_INT)
-	set(FDELT_TYPE "long unsigned int")
-else()
-	set(FDELT_TYPE "long int")
-endif()
-
 # Activate wallet
 set(ENABLE_WALLET ${BUILD_BITCOIN_WALLET})
 
diff --git a/src/config/bitcoin-config.h.cmake.in b/src/config/bitcoin-config.h.cmake.in
--- a/src/config/bitcoin-config.h.cmake.in
+++ b/src/config/bitcoin-config.h.cmake.in
@@ -66,8 +66,6 @@
 #cmakedefine HAVE_FUNC_ATTRIBUTE_VISIBILITY 1
 #cmakedefine HAVE_FUNC_ATTRIBUTE_DLLEXPORT 1
 
-#define FDELT_TYPE ${FDELT_TYPE}
-
 #cmakedefine ENABLE_BIP70 1
 #cmakedefine ENABLE_WALLET 1
 #cmakedefine ENABLE_ZMQ 1