diff --git a/lib/dry/validation/rule.rb b/lib/dry/validation/rule.rb
index bc052675..f51dceed 100644
--- a/lib/dry/validation/rule.rb
+++ b/lib/dry/validation/rule.rb
@@ -82,7 +82,7 @@ def each(*macros, &block)
         @keys = []
 
         @block = proc do
-          unless result.base_error?(root) || !values.key?(root)
+          unless result.base_error?(root) || !values.key?(root) || values[root].nil?
             values[root].each_with_index do |_, idx|
               path = [*Schema::Path[root].to_a, idx]
 
diff --git a/lib/dry/validation/values.rb b/lib/dry/validation/values.rb
index 272745f4..588f6db4 100644
--- a/lib/dry/validation/values.rb
+++ b/lib/dry/validation/values.rb
@@ -65,7 +65,6 @@ def [](*args)
       def key?(key, hash = data)
         return hash.key?(key) if key.is_a?(Symbol)
 
-        # rubocop: disable Lint/DuplicateBranch
         Schema::Path[key].reduce(hash) do |a, e|
           if e.is_a?(Array)
             result = e.all? { |k| key?(k, a) }
@@ -81,8 +80,6 @@ def key?(key, hash = data)
           end
           a[e]
         end
-        # rubocop: enable Lint/DuplicateBranch
-
         true
       end
       # rubocop: enable Metrics/PerceivedComplexity
diff --git a/spec/unit/rule_spec.rb b/spec/unit/rule_spec.rb
index e91b1853..1aa2e363 100644
--- a/spec/unit/rule_spec.rb
+++ b/spec/unit/rule_spec.rb
@@ -50,4 +50,24 @@
       end
     end
   end
+
+  context "with an optional value" do
+    let(:contract_class) do
+      Class.new(Dry::Validation::Contract) do
+        schema do
+          required(:tags).maybe(:array)
+        end
+      end
+    end
+
+    context "when using .each macro" do
+      it "does not fail when input is nil" do
+        contract_class.rule(:tags).each do
+          key.failure("should not be called")
+        end
+
+        expect(contract.(tags: nil).errors.to_h).to eq({})
+      end
+    end
+  end
 end