...
diff --git a/configure.ac b/configure.ac
index 5eb9bd8..40df393 100644
--- a/configure.ac
+++ b/configure.ac
@@ -469,12 +469,10 @@
 AC_SUBST([pkgconfigdir])
 
 #
-# Enable support for threads
-#
-# Find Posix threads library
+# Enable support for POSIX thread APIs
 #
 AC_ARG_WITH([threads],
-    [AC_HELP_STRING([--without-threads], [disable threads support])],
+    [AC_HELP_STRING([--without-threads], [disable POSIX threads API support])],
     [with_threads=$withval],
     [with_threads='yes'])
 
@@ -487,7 +485,7 @@
         DEF_THREAD="$PTHREAD_CFLAGS"
         CFLAGS="$CFLAGS $DEF_THREAD"
         CXXFLAGS="$CXXFLAGS $DEF_THREAD"
-	THREAD_LIBS="$PTHREAD_LIBS"
+        THREAD_LIBS="$PTHREAD_LIBS"
         if test "$CC" != "$PTHREAD_CC"; then
             AC_MSG_WARN([Replacing compiler $CC with compiler $PTHREAD_CC to support pthreads.])
             CC="$PTHREAD_CC"