diff --git a/lib/blacklight/search_state.rb b/lib/blacklight/search_state.rb
index a6ce863ccb..55ed1297b2 100644
--- a/lib/blacklight/search_state.rb
+++ b/lib/blacklight/search_state.rb
@@ -37,6 +37,26 @@ def to_hash
     end
     alias to_h to_hash
 
+    def to_unsafe_h
+      Deprecation.warn(self, 'Use SearchState#to_h instead of SearchState#to_unsafe_h')
+      to_hash
+    end
+
+    def method_missing(method_name, *arguments, &block)
+      if @params.respond_to?(method_name)
+        Deprecation.warn(self, "Calling `#{method_name}` on Blacklight::SearchState " \
+          'is deprecated and will be removed in Blacklight 8. Call #to_h first if you ' \
+          ' need to use hash methods (or, preferably, use your own SearchState implementation)')
+        @params.public_send(method_name, *arguments, &block)
+      else
+        super
+      end
+    end
+
+    def respond_to_missing?(method_name, include_private = false)
+      @params.respond_to?(method_name, include_private) || super
+    end
+
     # Tiny shim to make it easier to migrate raw params access to using this class
     delegate :[], to: :params
     deprecation_deprecate :[]
diff --git a/spec/lib/blacklight/search_state_spec.rb b/spec/lib/blacklight/search_state_spec.rb
index 8e054b1f1b..014a946e86 100644
--- a/spec/lib/blacklight/search_state_spec.rb
+++ b/spec/lib/blacklight/search_state_spec.rb
@@ -48,6 +48,18 @@
     end
   end
 
+  describe 'interface compatibility with params' do
+    let(:params) { parameter_class.new f: { ff: ['xyz'] } }
+
+    it 'implements param methods' do
+      Deprecation.silence(described_class) do
+        expect(search_state.to_unsafe_h).to eq('f' => { 'ff' => ['xyz'] })
+        expect(search_state.fetch(:f)).to eq('ff' => ['xyz'])
+        expect(search_state.select { |k, _v,| k == 'f' }).to eq('f' => { 'ff' => ['xyz'] })
+      end
+    end
+  end
+
   describe '#query_param' do
     let(:params) { parameter_class.new q: 'xyz' }