diff --git a/lib/liquid/parser.rb b/lib/liquid/parser.rb
index 645dfa3a..00faefdc 100644
--- a/lib/liquid/parser.rb
+++ b/lib/liquid/parser.rb
@@ -48,7 +48,7 @@ module Liquid
 
     def expression
       token = @tokens[@p]
-      case token[0]
+      expr = case token[0]
       when :id
         str = consume
         str << variable_lookups
@@ -69,6 +69,21 @@ module Liquid
       else
         raise SyntaxError, "#{token} is not a valid expression"
       end
+      if look(:comparison)
+        operator = consume(:comparison)
+        left     = expr
+        right    = expression
+
+        "#{left} #{operator} #{right}"
+      elsif look(:boolean_operator)
+        operator = consume(:boolean_operator)
+        left     = expr
+        right    = expression
+
+        "#{left} #{operator} #{right}"
+      else
+        expr
+      end
     end
 
     def argument