diff --git a/extension/Makefile.am b/extension/Makefile.am
index df55b98..ab7f7bc 100644
--- a/extension/Makefile.am
+++ b/extension/Makefile.am
@@ -77,7 +77,11 @@ inplace_la_LIBADD     = $(MY_LIBS)
 # Solaris in addition wants the math library.
 intdiv_la_SOURCES     = intdiv.c
 intdiv_la_LDFLAGS     = $(MY_MODULE_FLAGS)
+if CYGWIN
 intdiv_la_LIBADD      = $(MY_LIBS) $(LIBMPFR) -lm
+else
+intdiv_la_LIBADD      = $(MY_LIBS)
+endif
 
 ordchr_la_SOURCES     = ordchr.c
 ordchr_la_LDFLAGS     = $(MY_MODULE_FLAGS)
diff --git a/extension/Makefile.in b/extension/Makefile.in
index f4bb628..7232782 100644
--- a/extension/Makefile.in
+++ b/extension/Makefile.in
@@ -187,7 +187,9 @@ inplace_la_OBJECTS = $(am_inplace_la_OBJECTS)
 inplace_la_LINK = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
 	$(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \
 	$(inplace_la_LDFLAGS) $(LDFLAGS) -o $@
-intdiv_la_DEPENDENCIES = $(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1)
address@hidden@intdiv_la_DEPENDENCIES = $(am__DEPENDENCIES_1)
address@hidden@intdiv_la_DEPENDENCIES = $(am__DEPENDENCIES_1) \
address@hidden@	$(am__DEPENDENCIES_1)
 am_intdiv_la_OBJECTS = intdiv.lo
 intdiv_la_OBJECTS = $(am_intdiv_la_OBJECTS)
 intdiv_la_LINK = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
@@ -562,7 +564,8 @@ inplace_la_LIBADD = $(MY_LIBS)
 # Solaris in addition wants the math library.
 intdiv_la_SOURCES = intdiv.c
 intdiv_la_LDFLAGS = $(MY_MODULE_FLAGS)
-intdiv_la_LIBADD = $(MY_LIBS) $(LIBMPFR) -lm
address@hidden@intdiv_la_LIBADD = $(MY_LIBS)
address@hidden@intdiv_la_LIBADD = $(MY_LIBS) $(LIBMPFR) -lm
 ordchr_la_SOURCES = ordchr.c
 ordchr_la_LDFLAGS = $(MY_MODULE_FLAGS)
 ordchr_la_LIBADD = $(MY_LIBS)
diff --git a/extension/configure b/extension/configure
index 2ace2d8..ceee83e 100755
--- a/extension/configure
+++ b/extension/configure
@@ -665,6 +665,8 @@ build
 LIBTOOL
 ac_ct_AR
 AR
+CYGWIN_FALSE
+CYGWIN_TRUE
 AM_BACKSLASH
 AM_DEFAULT_VERBOSITY
 AM_DEFAULT_V
@@ -4540,6 +4542,15 @@ if test "${enable_mpfr+set}" = set; then :
 fi
 
 
+ if uname | grep -i cygwin > /dev/null; then
+  CYGWIN_TRUE=
+  CYGWIN_FALSE='#'
+else
+  CYGWIN_TRUE='#'
+  CYGWIN_FALSE=
+fi
+
+
 ac_fn_c_check_member "$LINENO" "struct stat" "st_blksize" "ac_cv_member_struct_stat_st_blksize" "$ac_includes_default"
 if test "x$ac_cv_member_struct_stat_st_blksize" = xyes; then :
 
@@ -13280,6 +13291,10 @@ else
   am__EXEEXT_FALSE=
 fi
 
+if test -z "${CYGWIN_TRUE}" && test -z "${CYGWIN_FALSE}"; then
+  as_fn_error $? "conditional \"CYGWIN\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 
 : "${CONFIG_STATUS=./config.status}"
 ac_write_fail=0
diff --git a/extension/configure.ac b/extension/configure.ac
index 2b91336..c53172a 100644
--- a/extension/configure.ac
+++ b/extension/configure.ac
@@ -45,6 +45,9 @@ AC_ARG_ENABLE([mpfr],
 	fi
 )
 
+dnl check for Cygwin
+AM_CONDITIONAL([CYGWIN], [uname | grep -i cygwin > /dev/null])
+
 dnl checks for structure members
 AC_CHECK_MEMBERS([struct stat.st_blksize])