diff --git a/configure.ac b/configure.ac
index 24300ba1b..660bee0b6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -187,19 +187,19 @@ dnl  investigation of problems with "64" system and library calls on
 dnl  Darwin (MacOS X).  The libguile code (_scm.h) assumes that if a
 dnl  system has stat64, it will have all the other 64 APIs too; but on
 dnl  Darwin, stat64 is there but other APIs are missing.
-dnl 
+dnl
 dnl  It also appears, from the Darwin docs, that most system call APIs
 dnl  there (i.e. the traditional ones _without_ "64" in their names) have
 dnl  been 64-bit-capable for a long time now, so it isn't necessary to
 dnl  use "64" versions anyway.  For example, Darwin's off_t is 64-bit.
-dnl 
+dnl
 dnl  A similar problem has been reported for HP-UX:
 dnl  http://www.nabble.com/Building-guile-1.8.2-on-hpux-td13106681.html
-dnl 
+dnl
 dnl  Therefore, and also because a Guile without LARGEFILE64 support is
 dnl  better than no Guile at all, we provide this option to suppress
 dnl  trying to use "64" calls.
-dnl 
+dnl
 dnl  It may be that for some 64-bit function on Darwin/HP-UX we do need
 dnl  to use a "64" call, and hence that by using --without-64-calls we're
 dnl  missing out on that.  If so, someone can work on that in the future.
@@ -895,7 +895,7 @@ volatile complex double z = - _Complex_I;
 int
 main (void)
 {
-  z = csqrt (z);	
+  z = csqrt (z);
   if (creal (z) > 0.0)
     return 0;  /* good */
   else
@@ -1463,7 +1463,7 @@ CFLAGS="$old_CFLAGS"
 fi # with_threads=pthreads
 
 
-## Cross building	
+## Cross building
 if test "$cross_compiling" = "yes"; then
   AC_MSG_CHECKING([cc for build])
   ## /usr/bin/cc still uses wrong assembler
@@ -1471,8 +1471,8 @@ if test "$cross_compiling" = "yes"; then
   CC_FOR_BUILD="${CC_FOR_BUILD-PATH=/usr/bin:$PATH cc}"
 else
   CC_FOR_BUILD="${CC_FOR_BUILD-$CC}"
-fi   
-     
+fi
+
 ## AC_MSG_CHECKING("if we are cross compiling")
 ## AC_MSG_RESULT($cross_compiling)
 if test "$cross_compiling" = "yes"; then
@@ -1496,7 +1496,7 @@ if test "$cross_compiling" = "yes"; then
   GUILE_FOR_BUILD="${GUILE_FOR_BUILD-guile}"
 else
   GUILE_FOR_BUILD='$(preinstguile)'
-fi   
+fi
 
 ## AC_MSG_CHECKING("if we are cross compiling")
 ## AC_MSG_RESULT($cross_compiling)