diff --git a/Misc/NEWS.d/next/Build/2026-01-08-22-27-07.gh-issue-85277.TotySi.rst b/Misc/NEWS.d/next/Build/2026-01-08-22-27-07.gh-issue-85277.TotySi.rst
new file mode 100644
index 00000000000000..538995538d7da8
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2026-01-08-22-27-07.gh-issue-85277.TotySi.rst
@@ -0,0 +1 @@
+Fix building without ``stropts.h`` or empty ``stropts.h``
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 49214d57a2e362..4c11d4cf895e31 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -9384,13 +9384,13 @@ os_openpty_impl(PyObject *module)
     if (_Py_set_inheritable(master_fd, 0, NULL) < 0)
         goto posix_error;
 
-#if !defined(__CYGWIN__) && !defined(__ANDROID__) && !defined(HAVE_DEV_PTC)
+#if defined(HAVE_STROPTS_H) && !defined(HAVE_DEV_PTC)
     ioctl(slave_fd, I_PUSH, "ptem"); /* push ptem */
     ioctl(slave_fd, I_PUSH, "ldterm"); /* push ldterm */
 #ifndef __hpux
     ioctl(slave_fd, I_PUSH, "ttcompat"); /* push ttcompat */
 #endif /* __hpux */
-#endif /* HAVE_CYGWIN */
+#endif /* defined(HAVE_STROPTS_H) && !defined(HAVE_DEV_PTC) */
 #endif /* HAVE_OPENPTY */
 
     return Py_BuildValue("(ii)", master_fd, slave_fd);
diff --git a/configure b/configure
index 411bc1a23226e7..5d632aedb62cbc 100755
--- a/configure
+++ b/configure
@@ -2335,6 +2335,60 @@ fi
 
 } # ac_fn_c_try_run
 
+# ac_fn_check_decl LINENO SYMBOL VAR INCLUDES EXTRA-OPTIONS FLAG-VAR
+# ------------------------------------------------------------------
+# Tests whether SYMBOL is declared in INCLUDES, setting cache variable VAR
+# accordingly. Pass EXTRA-OPTIONS to the compiler, using FLAG-VAR.
+ac_fn_check_decl ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  as_decl_name=`echo $2|sed 's/ *(.*//'`
+  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5
+printf %s "checking whether $as_decl_name is declared... " >&6; }
+if eval test \${$3+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`
+  eval ac_save_FLAGS=\$$6
+  as_fn_append $6 " $5"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main (void)
+{
+#ifndef $as_decl_name
+#ifdef __cplusplus
+  (void) $as_decl_use;
+#else
+  (void) $as_decl_name;
+#endif
+#endif
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  eval "$3=yes"
+else case e in #(
+  e) eval "$3=no" ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+  eval $6=\$ac_save_FLAGS
+ ;;
+esac
+fi
+eval ac_res=\$$3
+	       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
+printf "%s\n" "$ac_res" >&6; }
+  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+
+} # ac_fn_check_decl
+
 # ac_fn_c_check_type LINENO TYPE VAR INCLUDES
 # -------------------------------------------
 # Tests whether TYPE exists after having included INCLUDES, setting cache
@@ -2653,60 +2707,6 @@ printf "%s\n" "$ac_res" >&6; }
 
 } # ac_fn_c_check_func
 
-# ac_fn_check_decl LINENO SYMBOL VAR INCLUDES EXTRA-OPTIONS FLAG-VAR
-# ------------------------------------------------------------------
-# Tests whether SYMBOL is declared in INCLUDES, setting cache variable VAR
-# accordingly. Pass EXTRA-OPTIONS to the compiler, using FLAG-VAR.
-ac_fn_check_decl ()
-{
-  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
-  as_decl_name=`echo $2|sed 's/ *(.*//'`
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking whether $as_decl_name is declared" >&5
-printf %s "checking whether $as_decl_name is declared... " >&6; }
-if eval test \${$3+y}
-then :
-  printf %s "(cached) " >&6
-else case e in #(
-  e) as_decl_use=`echo $2|sed -e 's/(/((/' -e 's/)/) 0&/' -e 's/,/) 0& (/g'`
-  eval ac_save_FLAGS=\$$6
-  as_fn_append $6 " $5"
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-$4
-int
-main (void)
-{
-#ifndef $as_decl_name
-#ifdef __cplusplus
-  (void) $as_decl_use;
-#else
-  (void) $as_decl_name;
-#endif
-#endif
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"
-then :
-  eval "$3=yes"
-else case e in #(
-  e) eval "$3=no" ;;
-esac
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
-  eval $6=\$ac_save_FLAGS
- ;;
-esac
-fi
-eval ac_res=\$$3
-	       { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_res" >&5
-printf "%s\n" "$ac_res" >&6; }
-  eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
-
-} # ac_fn_check_decl
-
 # ac_fn_c_check_member LINENO AGGR MEMBER VAR INCLUDES
 # ----------------------------------------------------
 # Tries to find if the field MEMBER exists in type AGGR, after including
@@ -11455,12 +11455,6 @@ if test "x$ac_cv_header_spawn_h" = xyes
 then :
   printf "%s\n" "#define HAVE_SPAWN_H 1" >>confdefs.h
 
-fi
-ac_fn_c_check_header_compile "$LINENO" "stropts.h" "ac_cv_header_stropts_h" "$ac_includes_default"
-if test "x$ac_cv_header_stropts_h" = xyes
-then :
-  printf "%s\n" "#define HAVE_STROPTS_H 1" >>confdefs.h
-
 fi
 ac_fn_c_check_header_compile "$LINENO" "sys/audioio.h" "ac_cv_header_sys_audioio_h" "$ac_includes_default"
 if test "x$ac_cv_header_sys_audioio_h" = xyes
@@ -11945,6 +11939,105 @@ fi
 fi
 
 
+# On Linux, stropts.h may be empty
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC options needed to detect all undeclared functions" >&5
+printf %s "checking for $CC options needed to detect all undeclared functions... " >&6; }
+if test ${ac_cv_c_undeclared_builtin_options+y}
+then :
+  printf %s "(cached) " >&6
+else case e in #(
+  e) ac_save_CFLAGS=$CFLAGS
+   ac_cv_c_undeclared_builtin_options='cannot detect'
+   for ac_arg in '' -fno-builtin; do
+     CFLAGS="$ac_save_CFLAGS $ac_arg"
+     # This test program should *not* compile successfully.
+     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+(void) strchr;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+
+else case e in #(
+  e) # This test program should compile successfully.
+        # No library function is consistently available on
+        # freestanding implementations, so test against a dummy
+        # declaration.  Include always-available headers on the
+        # off chance that they somehow elicit warnings.
+        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <float.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stddef.h>
+extern void ac_decl (int, char *);
+
+int
+main (void)
+{
+(void) ac_decl (0, (char *) 0);
+  (void) ac_decl;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+  if test x"$ac_arg" = x
+then :
+  ac_cv_c_undeclared_builtin_options='none needed'
+else case e in #(
+  e) ac_cv_c_undeclared_builtin_options=$ac_arg ;;
+esac
+fi
+          break
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
+esac
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+    done
+    CFLAGS=$ac_save_CFLAGS
+   ;;
+esac
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_undeclared_builtin_options" >&5
+printf "%s\n" "$ac_cv_c_undeclared_builtin_options" >&6; }
+  case $ac_cv_c_undeclared_builtin_options in #(
+  'cannot detect') :
+    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
+printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
+as_fn_error $? "cannot make $CC report undeclared builtins
+See 'config.log' for more details" "$LINENO" 5; } ;; #(
+  'none needed') :
+    ac_c_undeclared_builtin_options='' ;; #(
+  *) :
+    ac_c_undeclared_builtin_options=$ac_cv_c_undeclared_builtin_options ;;
+esac
+
+ac_fn_check_decl "$LINENO" "I_PUSH" "ac_cv_have_decl_I_PUSH" "
+    #ifdef HAVE_SYS_TYPES_H
+    #  include <sys/types.h>
+    #endif
+    #include <stropts.h>
+
+" "$ac_c_undeclared_builtin_options" "CFLAGS"
+if test "x$ac_cv_have_decl_I_PUSH" = xyes
+then :
+
+
+printf "%s\n" "#define HAVE_STROPTS_H 1" >>confdefs.h
+
+fi
+
 # bluetooth/bluetooth.h has been known to not compile with -std=c99.
 # http://permalink.gmane.org/gmane.linux.bluez.kernel/22294
 SAVE_CFLAGS=$CFLAGS
@@ -20481,89 +20574,6 @@ fi
 
 fi
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $CC options needed to detect all undeclared functions" >&5
-printf %s "checking for $CC options needed to detect all undeclared functions... " >&6; }
-if test ${ac_cv_c_undeclared_builtin_options+y}
-then :
-  printf %s "(cached) " >&6
-else case e in #(
-  e) ac_save_CFLAGS=$CFLAGS
-   ac_cv_c_undeclared_builtin_options='cannot detect'
-   for ac_arg in '' -fno-builtin; do
-     CFLAGS="$ac_save_CFLAGS $ac_arg"
-     # This test program should *not* compile successfully.
-     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main (void)
-{
-(void) strchr;
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"
-then :
-
-else case e in #(
-  e) # This test program should compile successfully.
-        # No library function is consistently available on
-        # freestanding implementations, so test against a dummy
-        # declaration.  Include always-available headers on the
-        # off chance that they somehow elicit warnings.
-        cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <float.h>
-#include <limits.h>
-#include <stdarg.h>
-#include <stddef.h>
-extern void ac_decl (int, char *);
-
-int
-main (void)
-{
-(void) ac_decl (0, (char *) 0);
-  (void) ac_decl;
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"
-then :
-  if test x"$ac_arg" = x
-then :
-  ac_cv_c_undeclared_builtin_options='none needed'
-else case e in #(
-  e) ac_cv_c_undeclared_builtin_options=$ac_arg ;;
-esac
-fi
-          break
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext ;;
-esac
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
-    done
-    CFLAGS=$ac_save_CFLAGS
-   ;;
-esac
-fi
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_undeclared_builtin_options" >&5
-printf "%s\n" "$ac_cv_c_undeclared_builtin_options" >&6; }
-  case $ac_cv_c_undeclared_builtin_options in #(
-  'cannot detect') :
-    { { printf "%s\n" "$as_me:${as_lineno-$LINENO}: error: in '$ac_pwd':" >&5
-printf "%s\n" "$as_me: error: in '$ac_pwd':" >&2;}
-as_fn_error $? "cannot make $CC report undeclared builtins
-See 'config.log' for more details" "$LINENO" 5; } ;; #(
-  'none needed') :
-    ac_c_undeclared_builtin_options='' ;; #(
-  *) :
-    ac_c_undeclared_builtin_options=$ac_cv_c_undeclared_builtin_options ;;
-esac
-
 ac_fn_check_decl "$LINENO" "dirfd" "ac_cv_have_decl_dirfd" "#include <sys/types.h>
                #include <dirent.h>
 " "$ac_c_undeclared_builtin_options" "CFLAGS"
diff --git a/configure.ac b/configure.ac
index 9e63c8f6144c3d..a7fca1fcdb949c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3010,7 +3010,7 @@ AC_CHECK_HEADERS([ \
   io.h langinfo.h libintl.h libutil.h linux/auxvec.h sys/auxv.h linux/fs.h linux/limits.h linux/memfd.h \
   linux/netfilter_ipv4.h linux/random.h linux/soundcard.h linux/sched.h \
   linux/tipc.h linux/wait.h netdb.h net/ethernet.h netinet/in.h netpacket/packet.h poll.h process.h pthread.h pty.h \
-  sched.h setjmp.h shadow.h signal.h spawn.h stropts.h sys/audioio.h sys/bsdtty.h sys/devpoll.h \
+  sched.h setjmp.h shadow.h signal.h spawn.h sys/audioio.h sys/bsdtty.h sys/devpoll.h \
   sys/endian.h sys/epoll.h sys/event.h sys/eventfd.h sys/file.h sys/ioctl.h sys/kern_control.h \
   sys/loadavg.h sys/lock.h sys/memfd.h sys/mkdev.h sys/mman.h sys/modem.h sys/param.h sys/pidfd.h sys/poll.h \
   sys/random.h sys/resource.h sys/select.h sys/sendfile.h sys/socket.h sys/soundcard.h sys/stat.h \
@@ -3021,6 +3021,16 @@ AC_CHECK_HEADERS([ \
 AC_HEADER_DIRENT
 AC_HEADER_MAJOR
 
+# On Linux, stropts.h may be empty
+AC_CHECK_DECL([I_PUSH], [
+  AC_DEFINE([HAVE_STROPTS_H], [1],
+    [Define to 1 if you have the <stropts.h> header file.])], [], [
+    #ifdef HAVE_SYS_TYPES_H
+    #  include <sys/types.h>
+    #endif
+    #include <stropts.h>
+])
+
 # bluetooth/bluetooth.h has been known to not compile with -std=c99.
 # http://permalink.gmane.org/gmane.linux.bluez.kernel/22294
 SAVE_CFLAGS=$CFLAGS