--- bin/automake.in.orig	2015-01-05 19:25:55 UTC
+++ bin/automake.in
@@ -3878,7 +3878,7 @@ sub substitute_ac_subst_variables_worker
 sub substitute_ac_subst_variables
 {
   my ($text) = @_;
-  $text =~ s/\${([^ \t=:+{}]+)}/substitute_ac_subst_variables_worker ($1)/ge;
+  $text =~ s/\$\{([^ \t=:+{}]+)\}/substitute_ac_subst_variables_worker ($1)/ge;
   return $text;
 }