diff --git a/ddclient.in b/ddclient.in
index f4f4ca3..2b18017 100755
--- a/ddclient.in
+++ b/ddclient.in
@@ -2594,7 +2594,8 @@ sub check_value {
 
     } elsif ($type eq T_PROTO) {
         $value = lc $value;
-        die("invalid $type: $orig\n") if !exists $protocols{$value};
+        die("invalid $type: $orig\nSupported values: ", join(' ', sort(keys(%protocols))), "\n")
+            if !exists $protocols{$value};
 
     } elsif ($type eq T_URL) {
         die("invalid $type: $orig\n")
@@ -2603,16 +2604,19 @@ sub check_value {
     } elsif ($type eq T_USE) {
         $value = lc $value;
         $value = 'disabled' if $value eq 'no';  # backwards compatibility
-        die("invalid $type: $orig\n") if !exists($ip_strategies{$value});
+        die(map(($_, "\n"), "invalid $type: $orig", 'Supported values:', ip_strategies_usage()))
+            if !exists($ip_strategies{$value});
 
     } elsif ($type eq T_USEV4) {
         $value = lc $value;
-        die("invalid $type: $orig\n") if !exists($ipv4_strategies{$value});
+        die(map(($_, "\n"), "invalid $type: $orig", 'Supported values:', ipv4_strategies_usage()))
+            if !exists($ipv4_strategies{$value});
 
     } elsif ($type eq T_USEV6) {
         $value = lc $value;
         $value = 'disabled' if $value eq 'no';  # backwards compatibility
-        die("invalid $type: $orig\n") if !exists($ipv6_strategies{$value});
+        die(map(($_, "\n"), "invalid $type: $orig", 'Supported values:', ipv6_strategies_usage()))
+            if !exists($ipv6_strategies{$value});
 
     } elsif ($type eq T_FILE) {
         die("invalid $type: $orig\n") if $value eq "";