diff --git a/cmd/csaf_aggregator/config.go b/cmd/csaf_aggregator/config.go
index e08ee52..ef97a60 100644
--- a/cmd/csaf_aggregator/config.go
+++ b/cmd/csaf_aggregator/config.go
@@ -228,10 +228,15 @@ func loadConfig(path string) (*config, error) {
 	}
 
 	var cfg config
-	if _, err := toml.DecodeFile(path, &cfg); err != nil {
+	md, err := toml.DecodeFile(path, &cfg)
+	if err != nil {
 		return nil, err
 	}
 
+	if undecoded := md.Undecoded(); len(undecoded) != 0 {
+		return nil, fmt.Errorf("could not parse %q from config.toml", undecoded)
+	}
+
 	cfg.setDefaults()
 
 	if err := cfg.check(); err != nil {
diff --git a/cmd/csaf_provider/config.go b/cmd/csaf_provider/config.go
index ad008df..2b07ab6 100644
--- a/cmd/csaf_provider/config.go
+++ b/cmd/csaf_provider/config.go
@@ -222,10 +222,16 @@ func loadConfig() (*config, error) {
 		path = defaultConfigPath
 	}
 	var cfg config
-	if _, err := toml.DecodeFile(path, &cfg); err != nil {
+
+	md, err := toml.DecodeFile(path, &cfg)
+	if err != nil {
 		return nil, err
 	}
 
+	if undecoded := md.Undecoded(); len(undecoded) != 0 {
+		return nil, fmt.Errorf("could not parse %q from config.toml", undecoded)
+	}
+
 	// Preset defaults
 
 	if cfg.OpenPGPPrivateKey == "" {
diff --git a/cmd/csaf_provider/main.go b/cmd/csaf_provider/main.go
index fbe3dd7..da409b2 100644
--- a/cmd/csaf_provider/main.go
+++ b/cmd/csaf_provider/main.go
@@ -47,7 +47,8 @@ func main() {
 	cfg, err := loadConfig()
 	if err != nil {
 		cgi.Serve(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
-			http.Error(rw, fmt.Sprintf("Config error: %v\n", err), http.StatusInternalServerError)
+			http.Error(rw, "Something went wrong. Check server logs for more details",
+				http.StatusInternalServerError)
 		}))
 		log.Fatalf("error: %v\n", err)
 	}