diff --git a/lib/css_parser/rule_set.rb b/lib/css_parser/rule_set.rb
index 82cbc87..99ae5bb 100644
--- a/lib/css_parser/rule_set.rb
+++ b/lib/css_parser/rule_set.rb
@@ -359,9 +359,8 @@ def expand_dimensions_shorthand! # :nodoc:
         #
         # TODO: rgba, hsl, hsla
         value.gsub!(RE_COLOUR) { |c| c.gsub(/(\s*,\s*)/, ',') }
-        value.gsub!(RE_FUNCTIONS) { |c| c.gsub(/\s+/, WHITESPACE_REPLACEMENT) }
 
-        matches = value.strip.split(/\s+/)
+        matches = split_value_preserving_whitespace(value)
 
         case matches.length
         when 1
@@ -640,6 +639,21 @@ def parse_selectors!(selectors) # :nodoc:
         s
       end
     end
+
+    def split_value_preserving_whitespace(value)
+      split_value = value.gsub(RE_FUNCTIONS) do |c|
+        c.gsub!(/\s+/, WHITESPACE_REPLACEMENT)
+        c
+      end
+
+      matches = split_value.strip.split(/\s+/)
+
+      matches.each do |c|
+        c.gsub!(WHITESPACE_REPLACEMENT, ' ')
+      end
+
+      matches
+    end
   end
 
   class OffsetAwareRuleSet < RuleSet