diff --git a/scripts/owlps-aggcheck.pl b/scripts/owlps-aggcheck.pl
index d51fbd4..8bc08fd 100755
--- a/scripts/owlps-aggcheck.pl
+++ b/scripts/owlps-aggcheck.pl
@@ -313,7 +313,7 @@ if ($print_stats) {
 
 if ($print_distribution) {
     foreach my $mac_trx (sort keys %distribution) {
-        foreach my $mac_cp (sort keys $distribution{$mac_trx}) {
+        foreach my $mac_cp (sort keys %{$distribution{$mac_trx}}) {
             # Let's pick a shortcut
             my $distrib = $distribution{$mac_trx}{$mac_cp};
 
@@ -322,7 +322,7 @@ if ($print_distribution) {
 
             # Make a list of SSs to print (we want to print all the SSs in the
             # interval, not just the SSs we found)
-            my @present_ss_list = sort { $a <=> $b } keys $distrib;
+            my @present_ss_list = sort { $a <=> $b } keys %{$distrib};
             my @ss_list = $present_ss_list[0] .. $present_ss_list[-1];
 
             # Print all the SSs