diff --git a/lib/mail/fields/content_disposition_field.rb b/lib/mail/fields/content_disposition_field.rb
index 97c277f98..52ffca9e2 100644
--- a/lib/mail/fields/content_disposition_field.rb
+++ b/lib/mail/fields/content_disposition_field.rb
@@ -14,7 +14,13 @@ def initialize(value = nil, charset = nil)
     end
 
     def element
-      @element ||= Mail::ContentDispositionElement.new(value)
+      @element ||=
+        begin
+          Mail::ContentDispositionElement.new(value)
+        rescue Mail::Field::ParseError
+          # Sanitize the value, handle special cases
+          Mail::ContentDispositionElement.new(sanitize(value))
+        end
     end
 
     def disposition_type
@@ -40,5 +46,14 @@ def decoded
       p = "; #{parameters.decoded}" if parameters.length > 0
       "#{disposition_type}#{p}"
     end
+
+    private
+
+    def sanitize(val)
+      val.
+        gsub(/\s*=\s*/,'='). # remove whitespaces around equal sign
+        gsub(/[; ]+/, '; '). # use '; ' as a separator (or EOL)
+        gsub(/;\s*$/,'') # remove trailing to keep examples below
+    end
   end
 end
diff --git a/lib/mail/fields/content_type_field.rb b/lib/mail/fields/content_type_field.rb
index 686d533ae..1c1ba3233 100644
--- a/lib/mail/fields/content_type_field.rb
+++ b/lib/mail/fields/content_type_field.rb
@@ -42,14 +42,6 @@ def element
         end
     end
 
-    def attempt_to_clean
-      # Sanitize the value, handle special cases
-      Mail::ContentTypeElement.new(sanitize(value))
-    rescue Mail::Field::ParseError
-      # All else fails, just get the MIME media type
-      Mail::ContentTypeElement.new(get_mime_type(value))
-    end
-
     def main_type
       @main_type ||= element.main_type
     end
@@ -103,6 +95,14 @@ def decoded
 
     private
 
+    def attempt_to_clean
+      # Sanitize the value, handle special cases
+      Mail::ContentTypeElement.new(sanitize(value))
+    rescue Mail::Field::ParseError
+      # All else fails, just get the MIME media type
+      Mail::ContentTypeElement.new(get_mime_type(value))
+    end
+
     def method_missing(name, *args, &block)
       if name.to_s =~ /(\w+)=/
         self.parameters[$1] = args.first
diff --git a/spec/mail/fields/content_disposition_field_spec.rb b/spec/mail/fields/content_disposition_field_spec.rb
index 38f791b2a..af114d1fc 100644
--- a/spec/mail/fields/content_disposition_field_spec.rb
+++ b/spec/mail/fields/content_disposition_field_spec.rb
@@ -109,5 +109,11 @@
       c = Mail::ContentDispositionField.new(string)
       expect(c.filename).to eq "Eelanalüüsi päring.jpg"
     end
+
+    it "should accept with whitespace around equal sign" do
+      string = %q{attachment; name = mikel.jpg}
+      c = Mail::ContentDispositionField.new(string)
+      expect(c.filename).to eq 'mikel.jpg'
+    end
   end
 end
diff --git a/spec/mail/fields/content_type_field_spec.rb b/spec/mail/fields/content_type_field_spec.rb
index 5753faf17..291c1e111 100644
--- a/spec/mail/fields/content_type_field_spec.rb
+++ b/spec/mail/fields/content_type_field_spec.rb
@@ -661,6 +661,11 @@
       expect(c.encoded).to eq result
     end
 
+    it "should accept with whitespace around equal sign" do
+      string = %q{application/octet-stream; filename = mikel.jpg}
+      c = Mail::ContentTypeField.new(string)
+      expect(c.filename).to eq 'mikel.jpg'
+    end
   end
 
   describe "handling badly formated content-type fields" do