diff --git a/.travis.yml b/.travis.yml
index 6791508b4..4199554dc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,22 +25,18 @@ matrix:
       jdk: oraclejdk8
       env: RAILS_VERSIONS=3.0
 
-    - rvm: 2.3
+    - rvm: 2.3.8
       jdk: oraclejdk8
       env: RAILS_VERSIONS=5.0
 
-    - rvm: 2.4
+    - rvm: 2.6.1
       jdk: oraclejdk8
-      env: RAILS_VERSIONS=5.0
+      env: RAILS_VERSIONS=4.0,5.0
 
-    - rvm: jruby-9.1
+    - rvm: jruby-9.2.5.0
       jdk: oraclejdk8
       env: RAILS_VERSIONS=5.0
 
-    - rvm: 2.5
-      jdk: oraclejdk8
-      env: RAILS_VERSIONS=4.0,5.0
-
 env:
   global:
     - ELASTICSEARCH_VERSION=6.4.0
@@ -53,8 +49,8 @@ before_install:
   - shasum -a 512 -c elasticsearch-${ELASTICSEARCH_VERSION}.deb.sha512
   - sudo dpkg -i --force-confnew elasticsearch-${ELASTICSEARCH_VERSION}.deb
   - sudo service elasticsearch start
-  - gem update --system -q
-  - gem update bundler -q
+  - gem update --system
+  - gem update bundler
   - gem --version
   - bundle version
 
diff --git a/elasticsearch-model/lib/elasticsearch/model/indexing.rb b/elasticsearch-model/lib/elasticsearch/model/indexing.rb
index 0fb5ff862..a88dd12fb 100644
--- a/elasticsearch-model/lib/elasticsearch/model/indexing.rb
+++ b/elasticsearch-model/lib/elasticsearch/model/indexing.rb
@@ -269,7 +269,8 @@ def delete_index!(options={})
             self.client.indices.delete index: target_index
           rescue Exception => e
             if e.class.to_s =~ /NotFound/ && options[:force]
-              STDERR.puts "[!!!] Index does not exist (#{e.class})"
+              client.transport.logger.debug("[!!!] Index does not exist (#{e.class})") if client.transport.logger
+              nil
             else
               raise e
             end
@@ -295,7 +296,8 @@ def refresh_index!(options={})
             self.client.indices.refresh index: target_index
           rescue Exception => e
             if e.class.to_s =~ /NotFound/ && options[:force]
-              STDERR.puts "[!!!] Index does not exist (#{e.class})"
+              client.transport.logger.debug("[!!!] Index does not exist (#{e.class})") if client.transport.logger
+              nil
             else
               raise e
             end
diff --git a/elasticsearch-model/spec/elasticsearch/model/indexing_spec.rb b/elasticsearch-model/spec/elasticsearch/model/indexing_spec.rb
index 7040d4992..54656d4df 100644
--- a/elasticsearch-model/spec/elasticsearch/model/indexing_spec.rb
+++ b/elasticsearch-model/spec/elasticsearch/model/indexing_spec.rb
@@ -612,7 +612,7 @@ class ::DummyIndexingModelForRecreate
     context 'when the index is not found' do
 
       let(:client) do
-        double('client', indices: indices)
+        double('client', indices: indices, transport: double('transport', { logger: nil }))
       end
 
       let(:indices) do
@@ -622,7 +622,7 @@ class ::DummyIndexingModelForRecreate
       end
 
       before do
-        expect(DummyIndexingModelForRecreate).to receive(:client).and_return(client)
+        expect(DummyIndexingModelForRecreate).to receive(:client).at_most(3).times.and_return(client)
       end
 
       context 'when the force option is true' do
@@ -630,6 +630,26 @@ class ::DummyIndexingModelForRecreate
         it 'deletes the index without raising an exception' do
           expect(DummyIndexingModelForRecreate.delete_index!(force: true)).to be_nil
         end
+
+        context 'when the client has a logger' do
+
+          let(:logger) do
+            Logger.new(STDOUT).tap { |l| l.level = Logger::DEBUG }
+          end
+
+          let(:client) do
+            double('client', indices: indices, transport: double('transport', { logger: logger }))
+          end
+
+          it 'deletes the index without raising an exception' do
+            expect(DummyIndexingModelForRecreate.delete_index!(force: true)).to be_nil
+          end
+
+          it 'logs the message that the index is not found' do
+            expect(logger).to receive(:debug)
+            expect(DummyIndexingModelForRecreate.delete_index!(force: true)).to be_nil
+          end
+        end
       end
 
       context 'when the force option is not provided' do
@@ -799,6 +819,8 @@ class ::DummyIndexingModelForCreate
         expect(DummyIndexingModelForCreate.create_index!(index: 'custom-foo'))
       end
     end
+
+    context 'when the logging level is debug'
   end
 
   describe '#refresh_index!' do
@@ -824,7 +846,7 @@ class ::DummyIndexingModelForRefresh
     end
 
     let(:client) do
-      double('client', indices: indices)
+      double('client', indices: indices, transport: double('transport', { logger: nil }))
     end
 
     let(:indices) do
@@ -832,7 +854,7 @@ class ::DummyIndexingModelForRefresh
     end
 
     before do
-      expect(DummyIndexingModelForRefresh).to receive(:client).and_return(client)
+      expect(DummyIndexingModelForRefresh).to receive(:client).at_most(3).times.and_return(client)
     end
 
     context 'when the force option is true' do
@@ -846,6 +868,26 @@ class ::DummyIndexingModelForRefresh
         it 'does not raise an exception' do
           expect(DummyIndexingModelForRefresh.refresh_index!(force: true)).to be_nil
         end
+
+        context 'when the client has a logger' do
+
+          let(:logger) do
+            Logger.new(STDOUT).tap { |l| l.level = Logger::DEBUG }
+          end
+
+          let(:client) do
+            double('client', indices: indices, transport: double('transport', { logger: logger }))
+          end
+
+          it 'does not raise an exception' do
+            expect(DummyIndexingModelForRefresh.refresh_index!(force: true)).to be_nil
+          end
+
+          it 'logs the message that the index is not found' do
+            expect(logger).to receive(:debug)
+            expect(DummyIndexingModelForRefresh.refresh_index!(force: true)).to be_nil
+          end
+        end
       end
 
       context 'when the operation raises another type of exception' do