diff --git a/lib/sass/script/number.rb b/lib/sass/script/number.rb
index 8872039e..6ce05cf3 100644
--- a/lib/sass/script/number.rb
+++ b/lib/sass/script/number.rb
@@ -155,9 +155,19 @@ module Sass::Script
     # @param other [Literal] The right-hand side of the operator
     # @return [Boolean] Whether this number is equal to the other object
     def eq(other)
-      Sass::Script::Bool.new(super.to_bool &&
-        self.numerator_units.sort == other.numerator_units.sort &&
-        self.denominator_units.sort == other.denominator_units.sort)
+      return Sass::Script::Bool.new(false) unless other.is_a?(Sass::Script::Number)
+      this = self
+      begin
+        if unitless?
+          this = this.coerce(other.numerator_units, other.denominator_units)
+        else
+          other = other.coerce(numerator_units, denominator_units)
+        end
+      rescue Sass::SyntaxError
+        return Sass::Script::Bool.new(false)
+      end
+
+      Sass::Script::Bool.new(this.value == other.value)
     end
 
     # The SassScript `>` operation.
@@ -253,7 +263,7 @@ module Sass::Script
 
     def operate(other, operation)
       this = self
-      if [:+, :-].include?(operation)
+      if [:+, :-, :<=, :<, :>, :>=].include?(operation)
         if unitless?
           this = this.coerce(other.numerator_units, other.denominator_units)
         else
diff --git a/lib/sass/tree/for_node.rb b/lib/sass/tree/for_node.rb
index 92600b70..02675130 100644
--- a/lib/sass/tree/for_node.rb
+++ b/lib/sass/tree/for_node.rb
@@ -28,14 +28,17 @@ module Sass::Tree
     # @return [Array<Tree::Node>] The resulting static nodes
     # @see Sass::Tree
     def _perform(environment)
-      from = @from.perform(environment).to_i
-      to = @to.perform(environment).to_i
-      range = Range.new(from, to, @exclusive)
+      from = @from.perform(environment)
+      to = @to.perform(environment)
+      if to.respond_to?(:coerce)
+        to = to.send(:coerce, from.numerator_units, from.denominator_units)
+      end
+      range = Range.new(from.to_i, to.to_i, @exclusive)
 
       children = []
       environment = Sass::Environment.new(environment)
       range.each do |i|
-        environment.set_local_var(@var, Sass::Script::Number.new(i))
+        environment.set_local_var(@var, Sass::Script::Number.new(i, from.numerator_units, from.denominator_units))
         children += perform_children(environment)
       end
       children
diff --git a/test/sass/engine_test.rb b/test/sass/engine_test.rb
index 67c47bdb..4803c2ef 100755
--- a/test/sass/engine_test.rb
+++ b/test/sass/engine_test.rb
@@ -76,8 +76,10 @@ class SassEngineTest < Test::Unit::TestCase
     "@if false\n@else if " => "Invalid else directive '@else if': expected 'if <expr>'.",
     "a\n  !b = 12\nc\n  d = !b" => 'Undefined variable: "!b".',
     "=foo\n  !b = 12\nc\n  +foo\n  d = !b" => 'Undefined variable: "!b".',
+    '@for !a from 1 to "2"' => '"2" is not an integer.',
     '@for !a from 1 to "foo"' => '"foo" is not an integer.',
     '@for !a from 1 to 1.232323' => '1.232 is not an integer.',
+    '@for !a from 1px to 3em' => "Incompatible units: 'em' and 'px'.",
     '@if' => "Invalid if directive '@if': expected expression.",
     '@while' => "Invalid while directive '@while': expected expression.",
     '@debug' => "Invalid debug directive '@debug': expected expression.",