diff --git a/lib/signrequest_client/api_client.rb b/lib/signrequest_client/api_client.rb
index 6ef0a63..47679fd 100644
--- a/lib/signrequest_client/api_client.rb
+++ b/lib/signrequest_client/api_client.rb
@@ -264,7 +264,7 @@ def sanitize_filename(filename)
     def build_request_url(path)
       # Add leading and trailing slashes to path
       path = "/#{path}".gsub(/\/+/, '/')
-      URI.encode(@config.base_url + path)
+      URI::DEFAULT_PARSER.escape(@config.base_url + path)
     end
 
     # Builds the HTTP request body
diff --git a/lib/signrequest_client/configuration.rb b/lib/signrequest_client/configuration.rb
index 6443e24..c0854b5 100644
--- a/lib/signrequest_client/configuration.rb
+++ b/lib/signrequest_client/configuration.rb
@@ -175,7 +175,7 @@ def base_path=(base_path)
 
     def base_url
       url = "#{scheme}://#{[host, base_path].join('/').gsub(/\/+/, '/')}".sub(/\/+\z/, '')
-      URI.encode(url)
+      URI::DEFAULT_PARSER.escape(url)
     end
 
     # Gets API key (with prefix if set).