diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0a74bf8391..b7b81f9add 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -151,11 +151,6 @@ if(WIN32)
 	set(EXTRA_INSTALLER_DIR ${_ws_lib_dir})
 
 	# XXX Add a dependency on ${_ws_lib_dir}/current_tag.txt?
-
-	# Prepopulate some ConfigureChecks values. Compilation checks
-	# on Windows can be slow.
-	set(HAVE_FCNTL_H TRUE)
-	set(HAVE_FLOORL TRUE)
 endif(WIN32)
 
 include(UseCustomIncludes)
diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
index 7d7ade8f2b..1181a7f375 100644
--- a/ConfigureChecks.cmake
+++ b/ConfigureChecks.cmake
@@ -13,7 +13,6 @@ include(CMakePushCheckState)
 include(CheckIncludeFile)
 include(CheckIncludeFiles)
 check_include_file("arpa/inet.h"            HAVE_ARPA_INET_H)
-check_include_file("fcntl.h"                HAVE_FCNTL_H)
 check_include_file("getopt.h"               HAVE_GETOPT_H)
 check_include_file("grp.h"                  HAVE_GRP_H)
 #
@@ -84,16 +83,6 @@ elseif(CMAKE_SYSTEM_NAME STREQUAL "SunOS" AND CMAKE_SYSTEM_VERSION MATCHES "5[.]
 	check_function_exists("getexecname"     HAVE_GETEXECNAME)
 endif()
 
-#
-# Use check_symbol_exists just in case math.h does something magic
-# and there's not actually a function named floorl()
-#
-cmake_push_check_state()
-set(CMAKE_REQUIRED_INCLUDES ${M_INCLUDE_DIRS})
-set(CMAKE_REQUIRED_LIBRARIES ${M_LIBRARIES})
-check_symbol_exists("floorl" "math.h"    HAVE_FLOORL)
-cmake_pop_check_state()
-
 #
 # Check whether we have clock_gettime().
 # It's not on Windows, so don't waste time checking for it.
diff --git a/cmakeconfig.h.in b/cmakeconfig.h.in
index d8ec896027..fe4bdd7392 100644
--- a/cmakeconfig.h.in
+++ b/cmakeconfig.h.in
@@ -43,9 +43,6 @@
 /* Define to 1 if you have the `clock_gettime` function. */
 #cmakedefine HAVE_CLOCK_GETTIME 1
 
-/* Define to 1 if you have the <fcntl.h> header file. */
-#cmakedefine HAVE_FCNTL_H 1
-
 /* Define to use the MaxMind DB library */
 #cmakedefine HAVE_MAXMINDDB 1
 
@@ -70,9 +67,6 @@
 /* Define if you have the 'getexecname' function. */
 #cmakedefine HAVE_GETEXECNAME 1
 
-/* Define if you have the 'floorl' function. */
-#cmakedefine HAVE_FLOORL 1
-
 /* Define to 1 if you have the getopt_long function. */
 #cmakedefine HAVE_GETOPT_LONG 1
 
diff --git a/ui/time_shift.c b/ui/time_shift.c
index 50d7562759..e0bf0b0615 100644
--- a/ui/time_shift.c
+++ b/ui/time_shift.c
@@ -19,10 +19,6 @@
 
 #include "ui/ws_ui_util.h"
 
-#ifndef HAVE_FLOORL
-#define floorl(x) floor((double)x)
-#endif
-
 #define SHIFT_POS               0
 #define SHIFT_NEG               1
 #define SHIFT_SETTOZERO         1
diff --git a/wsutil/file_util.h b/wsutil/file_util.h
index 2a756fbc25..7b83fba1fc 100644
--- a/wsutil/file_util.h
+++ b/wsutil/file_util.h
@@ -20,9 +20,7 @@
 #include <gmodule.h>
 #endif
 
-#ifdef HAVE_FCNTL_H
 #include <fcntl.h>	/* for open() */
-#endif
 
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>	/* for read(), write(), close(), etc. */