diff --git a/src/gl-compile-conf b/src/gl-compile-conf
index dcd2535..141f7d7 100755
--- a/src/gl-compile-conf
+++ b/src/gl-compile-conf
@@ -458,14 +458,20 @@ for my $pubkey (glob("*"))
     print STDERR "WARNING: pubkey $pubkey exists but user $user not in config\n"
         unless $user_list{$user};
     $user_list{$user} = 'has pubkey';
+    # apparently some pubkeys don't end in a newline...
+    my $pubkey_content = `cat $pubkey`;
+    $pubkey_content =~ s/\s*$/\n/;
+    # don't trust files with multiple lines (i.e., something after a newline)
+    if ($pubkey_content =~ /\n./)
+    {
+        print STDERR "WARNING: a pubkey file can only have one line (key); ignoring $pubkey\n";
+        next;
+    }
     if ($SHELL_USERS and $SHELL_USERS =~ /(^|\s)$user(\s|$)/) {
         print $newkeys_fh "command=\"$AUTH_COMMAND -s $user\",$AUTH_OPTIONS ";
     } else {
         print $newkeys_fh "command=\"$AUTH_COMMAND $user\",$AUTH_OPTIONS,no-pty ";
     }
-    # apparently some pubkeys don't end in a newline...
-    my $pubkey_content = `cat $pubkey`;
-    $pubkey_content =~ s/\s*$/\n/;
     print $newkeys_fh $pubkey_content;
 }
 # lint check 3; a little more severe than the first two I guess...