diff --git a/Build.pm b/Build.pm
index 9ab1b05d6..321db5878 100644
--- a/Build.pm
+++ b/Build.pm
@@ -111,10 +111,9 @@ sub unify {
   return grep(delete($h{$_}), @_);
 }
 
-sub define($)
-{
-  my $def = shift;
-  $extra_macros .= '%define '.$def."\n";
+sub define {
+  my ($def) = @_;
+  $extra_macros .= "%define $def\n";
 }
 
 sub init_helper_hashes {
@@ -451,6 +450,16 @@ sub read_config {
   return $config;
 }
 
+sub gettargetarchos {
+  my ($config) = @_;
+  my ($arch, $os);
+  for (@{$config->{'macros'} || []}) {
+    $arch = $1 if /^%define _target_cpu (\S+)/;
+    $os = $1 if /^%define _target_os (\S+)/;
+  }
+  return ($arch, $os);
+}
+
 sub do_subst {
   my ($config, @deps) = @_;
   my @res;
diff --git a/Build/Arch.pm b/Build/Arch.pm
index 3d25f46eb..074aaab7a 100644
--- a/Build/Arch.pm
+++ b/Build/Arch.pm
@@ -119,10 +119,7 @@ sub parse {
   $ret->{'deps'} = [];
   push @{$ret->{'deps'}}, @{$vars{$_} || []} for qw{makedepends checkdepends depends};
   # get arch from macros
-  my $arch;
-  for (@{$config->{'macros'} || []}) {
-    $arch = $1 if /^%define _target_cpu (\S+)/;
-  }
+  my ($arch) = Build::gettargetarchos($config);
   # map to arch linux name and add arch dependent
   $arch = 'i686' if $arch =~ /^i[345]86$/;
   push @{$ret->{'deps'}}, @{$vars{"${_}_$arch"} || []} for qw{makedepends checkdepends depends};
diff --git a/Build/Deb.pm b/Build/Deb.pm
index 16b81e58a..cf1abf2d5 100644
--- a/Build/Deb.pm
+++ b/Build/Deb.pm
@@ -62,13 +62,9 @@ sub parse {
   my @control;
 
   # get arch and os from macros
-  my ($arch, $os);
-  for (@{$bconf->{'macros'} || []}) {
-    $arch = $1 if /^%define _target_cpu (\S+)/;
-    $os = $1 if /^%define _target_os (\S+)/;
-  }
+  my ($arch, $os) = Build::gettargetarchos($bconf);
   # map to debian names
-  $os = 'linux' if !defined($os);
+  $os = 'linux' unless defined $os;
   $arch = basearch($arch);
 
   if (ref($fn) eq 'ARRAY') {
diff --git a/Build/Rpm.pm b/Build/Rpm.pm
index a6ebada7f..89bab63f6 100644
--- a/Build/Rpm.pm
+++ b/Build/Rpm.pm
@@ -187,15 +187,29 @@ sub grabargs {
   return \%m;
 }
 
+sub initmacros {
+  my ($config, $macros, $macros_args) = @_;
+  for my $line (@{$config->{'macros'} || []}) {
+    next unless $line =~ /^%define\s*([0-9a-zA-Z_]+)(?:\(([^\)]*)\))?\s*(.*?)$/;
+    my $macname = $1;
+    my $macargs = $2;
+    my $macbody = $3;
+    if (defined $macargs) {
+      $macros_args->{$macname} = $macargs;
+    } else {
+      delete $macros_args->{$macname};
+    }
+    $macros->{$macname} = $macbody;
+  }
+}
+
 sub expandmacros {
   my ($config, $line, $lineno, $macros, $macros_args) = @_;
 
   if (!$macros) {
     $macros = {};
     $macros_args = {};
-    for my $macline (@{$config->{'macros'} || []}) {
-      expandmacros($config, $macline, undef, $macros, $macros_args);
-    }
+    initmacros($config, $macros, $macros_args);
   }
   my $expandedline = '';
   my $tries = 0;
@@ -403,9 +417,7 @@ sub parse {
     return $ret;
   }
   
-  for my $line (@{$config->{'macros'} || []}) {
-    expandmacros($config, $line, undef, \%macros, \%macros_args);
-  }
+  initmacros($config, \%macros, \%macros_args);
   my $skip = 0;
   my $main_preamble = 1;
   my $preamble = 1;