diff --git a/.github/workflows/liquid.yml b/.github/workflows/liquid.yml
index ccc3c0d1..4722f60b 100644
--- a/.github/workflows/liquid.yml
+++ b/.github/workflows/liquid.yml
@@ -6,7 +6,6 @@ jobs:
     strategy:
       matrix:
         entry:
-          - { ruby: '2.5', allowed-failure: false }
           - { ruby: '2.7', allowed-failure: false }
           - { ruby: '3.0', allowed-failure: false }
           - { ruby: ruby-head, allowed-failure: true }
diff --git a/lib/liquid/c.rb b/lib/liquid/c.rb
index 2649c366..259c7d8f 100644
--- a/lib/liquid/c.rb
+++ b/lib/liquid/c.rb
@@ -86,7 +86,7 @@ def new_tokenizer(source, start_line_number: nil, for_liquid_tag: false)
 
   def parse_expression(markup)
     if liquid_c_nodes_disabled?
-      Liquid::Expression.ruby_parse(markup)
+      Liquid::Expression.parse(markup)
     else
       Liquid::C::Expression.lax_parse(markup)
     end
@@ -207,22 +207,17 @@ class << self
     def lax_parse(markup)
       strict_parse(markup)
     rescue Liquid::SyntaxError
-      Liquid::Expression.ruby_parse(markup)
+      Liquid::Expression.parse(markup)
     end
-  end
-end
-
-Liquid::Expression.class_eval do
-  class << self
-    alias_method :ruby_parse, :parse
 
-    def c_parse(markup)
-      Liquid::C::Expression.lax_parse(markup)
-    end
+    # Default to strict parsing, since Liquid::C::Expression.parse should only really
+    # be used with constant expressions.  Otherwise, prefer parse_context.parse_expression.
+    alias_method :parse, :strict_parse
   end
 end
 
 Liquid::Context.class_eval do
+  alias_method :ruby_parse_evaluate, :[]
   alias_method :ruby_evaluate, :evaluate
   alias_method :ruby_find_variable, :find_variable
   alias_method :ruby_strict_variables=, :strict_variables=
@@ -232,6 +227,10 @@ def c_parse(markup)
   def c_find_variable_kwarg(key, raise_on_not_found: true)
     c_find_variable(key, raise_on_not_found)
   end
+
+  def c_parse_evaluate(expression)
+    c_evaluate(Liquid::C::Expression.lax_parse(expression))
+  end
 end
 
 Liquid::ResourceLimits.class_eval do
@@ -256,15 +255,15 @@ class << self
       def enabled=(value)
         @enabled = value
         if value
+          Liquid::Context.send(:alias_method, :[], :c_parse_evaluate)
           Liquid::Context.send(:alias_method, :evaluate, :c_evaluate)
           Liquid::Context.send(:alias_method, :find_variable, :c_find_variable_kwarg)
           Liquid::Context.send(:alias_method, :strict_variables=, :c_strict_variables=)
-          Liquid::Expression.singleton_class.send(:alias_method, :parse, :c_parse)
         else
+          Liquid::Context.send(:alias_method, :[], :ruby_parse_evaluate)
           Liquid::Context.send(:alias_method, :evaluate, :ruby_evaluate)
           Liquid::Context.send(:alias_method, :find_variable, :ruby_find_variable)
           Liquid::Context.send(:alias_method, :strict_variables=, :ruby_strict_variables=)
-          Liquid::Expression.singleton_class.send(:alias_method, :parse, :ruby_parse)
         end
       end
     end
diff --git a/test/unit/expression_test.rb b/test/unit/expression_test.rb
index 08e1bae4..dbcf4433 100644
--- a/test/unit/expression_test.rb
+++ b/test/unit/expression_test.rb
@@ -159,7 +159,7 @@ def test_disassemble_int16
   end
 
   def test_disable_c_nodes
-    context = Liquid::Context.new({ "x" => 123 })
+    context = Liquid::Context.new({ "x" => 123, "y" => { 123 => 42 } })
 
     expr = Liquid::ParseContext.new.parse_expression("x")
     assert_instance_of(Liquid::C::Expression, expr)
@@ -168,6 +168,11 @@ def test_disable_c_nodes
     expr = Liquid::ParseContext.new(disable_liquid_c_nodes: true).parse_expression("x")
     assert_instance_of(Liquid::VariableLookup, expr)
     assert_equal(123, context.evaluate(expr))
+
+    expr = Liquid::ParseContext.new(disable_liquid_c_nodes: true).parse_expression("y[x]")
+    assert_instance_of(Liquid::VariableLookup, expr)
+    assert_instance_of(Liquid::VariableLookup, expr.lookups.first)
+    assert_equal(42, context.evaluate(expr))
   end
 
   private