diff --git a/changelog/fix_space_inside_block_braces_with_numbered_arguments.md b/changelog/fix_space_inside_block_braces_with_numbered_arguments.md
new file mode 100644
index 00000000000..e539c9617f0
--- /dev/null
+++ b/changelog/fix_space_inside_block_braces_with_numbered_arguments.md
@@ -0,0 +1 @@
+* [#10736](https://github.com/rubocop/rubocop/pull/10736): Fix Layout/SpaceInsideBlockBraces for blocks with numbered arguments. ([@gsamokovarov][])
diff --git a/lib/rubocop/cop/layout/space_inside_block_braces.rb b/lib/rubocop/cop/layout/space_inside_block_braces.rb
index 8a0d9a8fc1e..54c18d2c6f5 100644
--- a/lib/rubocop/cop/layout/space_inside_block_braces.rb
+++ b/lib/rubocop/cop/layout/space_inside_block_braces.rb
@@ -98,6 +98,8 @@ def on_block(node)
           check_inside(node, left_brace, right_brace)
         end
 
+        alias on_numblock on_block
+
         private
 
         def check_inside(node, left_brace, right_brace)
@@ -126,7 +128,7 @@ def adjacent_braces(left_brace, right_brace)
         end
 
         def braces_with_contents_inside(node, inner)
-          args_delimiter = node.arguments.loc.begin # Can be ( | or nil.
+          args_delimiter = node.arguments.loc.begin if node.block_type? # Can be ( | or nil.
 
           check_left_brace(inner, node.loc.begin, args_delimiter)
           check_right_brace(inner, node.loc.begin, node.loc.end, node.single_line?)
diff --git a/spec/rubocop/cop/layout/space_inside_block_braces_spec.rb b/spec/rubocop/cop/layout/space_inside_block_braces_spec.rb
index 10c22194f8d..735fbc30392 100644
--- a/spec/rubocop/cop/layout/space_inside_block_braces_spec.rb
+++ b/spec/rubocop/cop/layout/space_inside_block_braces_spec.rb
@@ -90,6 +90,20 @@
     end
   end
 
+  context 'Ruby >= 2.7', :ruby27 do
+    it 'registers an offense for numblocks without inner space' do
+      expect_offense(<<~RUBY)
+        [1, 2, 3].each {_1 * 2}
+                        ^ Space missing inside {.
+                              ^ Space missing inside }.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        [1, 2, 3].each { _1 * 2 }
+      RUBY
+    end
+  end
+
   it 'accepts braces surrounded by spaces' do
     expect_no_offenses('each { puts }')
   end