diff --git a/lib/fhir_client/client.rb b/lib/fhir_client/client.rb
index c6a0a8cd..a36ffb47 100644
--- a/lib/fhir_client/client.rb
+++ b/lib/fhir_client/client.rb
@@ -428,7 +428,7 @@ def get(path, headers = {})
       FHIR.logger.info "GETTING: #{url}"
       headers = clean_headers(headers) unless headers.empty?
       if @use_oauth2_auth
-        # @client.refresh!
+        refresh_oauth2_session
         begin
           response = @client.get(url, headers: headers)
         rescue => e
@@ -510,7 +510,7 @@ def post(path, resource, headers)
       headers = clean_headers(headers)
       payload = request_payload(resource, headers) if resource
       if @use_oauth2_auth
-        # @client.refresh!
+        refresh_oauth2_session
         begin
           response = @client.post(url, headers: headers, body: payload)
         rescue => e
@@ -557,7 +557,7 @@ def put(path, resource, headers)
       headers = clean_headers(headers)
       payload = request_payload(resource, headers) if resource
       if @use_oauth2_auth
-        # @client.refresh!
+        refresh_oauth2_session
         begin
           response = @client.put(url, headers: headers, body: payload)
         rescue => e
@@ -604,7 +604,7 @@ def patch(path, patchset, headers)
       headers = clean_headers(headers)
       payload = request_patch_payload(patchset, headers['Content-Type'])
       if @use_oauth2_auth
-        # @client.refresh!
+        refresh_oauth2_session
         begin
           response = @client.patch(url, headers: headers, body: payload)
         rescue => e
@@ -672,7 +672,7 @@ def delete(path, headers)
       FHIR.logger.info "DELETING: #{url}"
       headers = clean_headers(headers)
       if @use_oauth2_auth
-        # @client.refresh!
+        refresh_oauth2_session
         begin
           response = @client.delete(url, headers: headers)
         rescue => e
@@ -736,5 +736,10 @@ def build_url(path)
         "#{base_path(path)}#{path}"
       end
     end
+
+    def refresh_oauth2_session
+      return unless @use_oauth2_auth
+      @client = @client.refresh! if (@client.expired? && @client.refresh_token)
+    end
   end
 end