http://bugs.gentoo.org/159192

--- configure
+++ configure
@@ -1250,6 +1250,7 @@
 allargs='$@'
 infiles='$infiles'
 infile='$infile'
+shebang='`sed -n -e 1p $infile.in`'
 cb='$cb'
 cs='$cs'
 ce='$ce'
@@ -1273,7 +1274,11 @@
   *.1|*.5|*.8|*.man)
     cb=$mancomment; cs=$mancomment; ce=$mancomment;;
   *)
-    cb="#"; cs="#"; ce="#";;
+    case "$shebang" in
+    '#!'*) cb="$shebang";;
+    *)     cb="#";;
+    esac
+    cs="#"; ce="#";;
   esac
   echo "$cb"                                                    > $infile
   echo "$cs Generated automatically from $infile.in by the"     >> $infile