diff --git a/lib/prometheus_exporter/client.rb b/lib/prometheus_exporter/client.rb
index 2302bd4..fac774c 100644
--- a/lib/prometheus_exporter/client.rb
+++ b/lib/prometheus_exporter/client.rb
@@ -5,6 +5,8 @@
 
 module PrometheusExporter
   class Client
+    NAMING_VALIDATION_REGEX = /^[a-zA-Z_][a-zA-Z0-9_]*$/
+
     class RemoteMetric
       attr_reader :name, :type, :help
 
@@ -128,6 +130,8 @@ def find_registered_metric(name, type: nil, help: nil)
     end
 
     def send_json(obj)
+      return false unless valid_naming?(obj)
+
       payload =
         if @custom_labels
           if obj[:custom_labels]
@@ -269,6 +273,28 @@ def wait_for_empty_queue_with_timeout(timeout_seconds)
         sleep(0.05)
       end
     end
+
+    def valid_naming?(obj)
+      if obj[:name]
+        return false unless obj[:name].match?(NAMING_VALIDATION_REGEX)
+      end
+
+      custom_label_names = []
+      if obj[:custom_labels]
+        custom_label_names.concat(obj[:custom_labels].keys)
+      end
+
+      if @custom_labels
+        custom_label_names.concat(@custom_labels.keys)
+      end
+
+      return true if custom_label_names.empty?
+
+      custom_label_names.all? { |name|
+        str = name.to_s
+        str.match?(NAMING_VALIDATION_REGEX) && !str.start_with?("__")
+      }
+    end
   end
 
   class LocalClient < Client
diff --git a/test/client_test.rb b/test/client_test.rb
index 5505114..763da55 100644
--- a/test/client_test.rb
+++ b/test/client_test.rb
@@ -65,4 +65,25 @@ def test_overriding_logger
 
     assert_includes(logs.string, "dropping message cause queue is full")
   end
+
+  def test_invalid_naming
+    client = PrometheusExporter::Client.new(custom_labels: {"label" => 1})
+
+    refute_same(false, client.send_json({}))
+    refute_same(false, client.send_json({name: "valid_name"}))
+    refute_same(false, client.send_json({name: "__valid_name"}))
+    refute_same(false, client.send_json({name: "__valid_name_1"}))
+    refute_same(false, client.send_json({name: "__valid_name_1", custom_labels: {"valid_name" => "value"}}))
+    refute_same(false, client.send_json({name: "valid_name", custom_labels: {"_valid_name" => "value"}}))
+
+    assert_equal(false, client.send_json({name: "invalid-name"}))
+    assert_equal(false, client.send_json({name: "valid_name", custom_labels: {"__invalid_name" => "value"}}))
+    assert_equal(false, client.send_json({name: "valid_name", custom_labels: {"invalid-name" => "value"}}))
+
+    client.custom_labels = {"__invalid_name" => "value"}
+    assert_equal(false, client.send_json({}))
+
+    client.custom_labels = {"invalid-name" => "value"}
+    assert_equal(false, client.send_json({}))
+  end
 end