diff --git a/lib/ransack/search.rb b/lib/ransack/search.rb
index a8bf95f8..eb7405a4 100644
--- a/lib/ransack/search.rb
+++ b/lib/ransack/search.rb
@@ -24,7 +24,7 @@ def initialize(object, params = {}, options = {})
       params = params.to_unsafe_h if params.respond_to?(:to_unsafe_h)
       if params.is_a? Hash
         params = params.dup
-        params = params.transform_values { |v| v.is_a?(String) && strip_whitespace ? v.strip : v }
+        params = params.deep_transform_values { |v| v.is_a?(String) && strip_whitespace ? v.strip : v }
         params.delete_if { |k, v| [*v].all?{ |i| i.blank? && i != false } }
       else
         params = {}
diff --git a/spec/ransack/search_spec.rb b/spec/ransack/search_spec.rb
index 6426a20a..61b853ae 100644
--- a/spec/ransack/search_spec.rb
+++ b/spec/ransack/search_spec.rb
@@ -31,6 +31,14 @@ module Ransack
             .with({ 'name_eq' => 'foobar' })
             Search.new(Person, name_eq: '   foobar     ')
           end
+
+          describe 'nested search params with group conditions' do
+            it 'strips leading & trailing whitespace in all nested values before building' do
+              expect_any_instance_of(Search).to receive(:build)
+              .with({ 'g' => [{ 'm' => 'or', 'name_eq' => 'foobar' }] })
+              Search.new(Person, { g: [{ m: 'or', name_eq: '   foobar     ' }] })
+            end
+          end
         end
 
         context 'when whitespace_strip option is false' do