--- a/src/auto/configure
+++ b/src/auto/configure
@@ -641,7 +641,6 @@ TCL_SRC
 vi_cv_path_tcl
 PYTHON_OBJ
 PYTHON_SRC
-PYTHON_NOPROTO
 PYTHON_CFLAGS
 PYTHON_GETPATH_CFLAGS
 PYTHON_LIBS
@@ -5112,7 +5111,6 @@ fi
 	else
 	  PYTHON_CFLAGS="-I${vi_cv_path_python_pfx}/include/python${vi_cv_var_python_version} -I${vi_cv_path_python_epfx}/include/python${vi_cv_var_python_version}"
 	fi
-	PYTHON_NOPROTO=
 	PYTHON_SRC="if_python.c"
 		if test "x$MACOSX" = "xyes"; then
 	  PYTHON_OBJ="objects/if_python.o"
@@ -5124,7 +5122,7 @@ fi
 	fi
 	PYTHON_GETPATH_CFLAGS="-DPYTHONPATH='\"${vi_cv_path_pythonpath}\"' -DPREFIX='\"${vi_cv_path_python_pfx}\"' -DEXEC_PREFIX='\"${vi_cv_path_python_epfx}\"'"
 
-										{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if -pthread should be used" >&5
+								{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if -pthread should be used" >&5
 $as_echo_n "checking if -pthread should be used... " >&6; }
 	threadsafe_flag=
 	thread_lib=
@@ -5153,7 +5151,7 @@ main ()
 _ACEOF
 if ac_fn_c_try_link "$LINENO"; then :
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }; PYTHON_NOPROTO="$threadsafe_flag"
+$as_echo "yes" >&6; }; PYTHON_CFLAGS="$PYTHON_CFLAGS $threadsafe_flag"
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }; LIBS=$libs_save_old
@@ -5171,7 +5169,7 @@ rm -f core conftest.err conftest.$ac_obj
 $as_echo_n "checking if compile and link flags for Python are sane... " >&6; }
 	cflags_save=$CFLAGS
 	libs_save=$LIBS
-	CFLAGS="$CFLAGS $PYTHON_CFLAGS $PYTHON_NOPROTO"
+	CFLAGS="$CFLAGS $PYTHON_CFLAGS"
 	LIBS="$LIBS $PYTHON_LIBS"
 	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
@@ -5204,7 +5202,6 @@ rm -f core conftest.err conftest.$ac_obj
 	  PYTHON_OBJ=
 	  PYTHON_LIBS=
 	  PYTHON_CFLAGS=
-	  PYTHON_NOPROTO=
 	fi
 
       fi
@@ -5221,7 +5218,6 @@ fi
 
 
 
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking --enable-tclinterp argument" >&5
 $as_echo_n "checking --enable-tclinterp argument... " >&6; }
 # Check whether --enable-tclinterp was given.