Fix warnings with Ruby 2.x

2 files changed, 2 insertions, 2 deletions

diff --git a/lib/axlsx.rb b/lib/axlsx.rb
index 9dba9144..0fd8260c 100644
--- a/lib/axlsx.rb
+++ b/lib/axlsx.rb
@@ -206,7 +206,7 @@ module Axlsx
   # See https://www.owasp.org/index.php/CSV_Injection for details.
   # @return [Boolean]
   def self.escape_formulas
-    @escape_formulas.nil? ? false : @escape_formulas
+    !defined?(@escape_formulas) || @escape_formulas.nil? ? false : @escape_formulas
   end
 
   # Sets whether to treat values starting with an equals sign as formulas or as literal strings.
diff --git a/lib/axlsx/workbook/worksheet/worksheet.rb b/lib/axlsx/workbook/worksheet/worksheet.rb
index 38fb5254..b4cad5be 100644
--- a/lib/axlsx/workbook/worksheet/worksheet.rb
+++ b/lib/axlsx/workbook/worksheet/worksheet.rb
@@ -21,7 +21,7 @@ module Axlsx
       @sheet_protection = nil
       initialize_page_options(options)
       parse_options options
-      self.escape_formulas = wb.escape_formulas if @escape_formulas.nil?
+      self.escape_formulas = wb.escape_formulas unless defined? @escape_formulas
       @workbook.worksheets << self
       @sheet_id = index + 1
       yield self if block_given?