diff --git a/spec/adapter/base_spec.cr b/spec/adapter/base_spec.cr
index 2e3a6a94..14a953cc 100644
--- a/spec/adapter/base_spec.cr
+++ b/spec/adapter/base_spec.cr
@@ -461,6 +461,15 @@ describe Jennifer::Adapter::Base do
         adapter.connection_string(:root).should match(connection_string)
       end
     end
+
+    context "without username or password" do
+      it do
+        config.user = ""
+        config.password = ""
+        connection_string = /^#{adapter.class.protocol}\:\/\/#{config.host}/
+        adapter.connection_string(:root).should match(connection_string)
+      end
+    end
   end
 
   describe "#query_array" do
diff --git a/src/jennifer/adapter/base.cr b/src/jennifer/adapter/base.cr
index d7c3de84..a7935c8d 100644
--- a/src/jennifer/adapter/base.cr
+++ b/src/jennifer/adapter/base.cr
@@ -264,7 +264,7 @@ module Jennifer
           config.port.try(&.>(0)) ? config.port : nil,
           type.db? ? config.db : "",
           connection_query,
-          config.user,
+          config.user.blank? ? nil : config.user,
           config.password && !config.password.empty? ? config.password : nil
         ).to_s
       end