diff --git a/shard.yml b/shard.yml
index 8ab099c..8933554 100644
--- a/shard.yml
+++ b/shard.yml
@@ -22,10 +22,10 @@ dependencies:
     github: nulldotpro/LibGL
   imgui:
     github: oprypin/crystal-imgui
-    tag: v1.87
+    tag: v1.88
   imgui-backends:
     github: mattrberry/crystal-imgui-backends
-    tag: v1.87
+    tag: v1.88
 
 development_dependencies:
   stumpy_png:
diff --git a/src/crab/common/frontend/controllers/gba_controller.cr b/src/crab/common/frontend/controllers/gba_controller.cr
index 2951ff7..b59dcd9 100644
--- a/src/crab/common/frontend/controllers/gba_controller.cr
+++ b/src/crab/common/frontend/controllers/gba_controller.cr
@@ -30,74 +30,54 @@ class GBAController < Controller
 
   def render_windows : Nil
     if @debug_window
-      ImGui.begin("Video", pointerof(@debug_window))
-      if ImGui.begin_tab_bar "VideoTabBar"
-        render_palettes_tab_item if ImGui.begin_tab_item "Palettes"
-        ImGui.end_tab_bar
+      ImGui.window("Video", pointerof(@debug_window)) do
+        ImGui.tab_bar "VideoTabBar" do
+          render_palettes_tab_item
+        end
       end
-      ImGui.end
     end
     if @scheduler_window
       cycles = @emu.scheduler.cycles
-      ImGui.begin("Scheduler", pointerof(@scheduler_window))
-      ImGui.text("Total cycles: #{cycles}")
-      if ImGui.begin_table("Table", 2)
-        ImGui.table_setup_column("Cycles")
-        ImGui.table_setup_column("Type")
-        ImGui.table_headers_row
-        @emu.scheduler.events.each do |event|
-          ImGui.table_next_row
-          ImGui.table_set_column_index 0
-          ImGui.text_unformatted (event.cycles - cycles).to_s
-          ImGui.table_set_column_index 1
-          ImGui.text_unformatted event.type.to_s
+      ImGui.window("Scheduler", pointerof(@scheduler_window)) do
+        ImGui.text("Total cycles: #{cycles}")
+        ImGui.table("Table", 2) do
+          ImGui.table_setup_column("Cycles")
+          ImGui.table_setup_column("Type")
+          ImGui.table_headers_row
+          @emu.scheduler.events.each do |event|
+            ImGui.table_next_row
+            ImGui.table_set_column_index 0
+            ImGui.text_unformatted (event.cycles - cycles).to_s
+            ImGui.table_set_column_index 1
+            ImGui.text_unformatted event.type.to_s
+          end
         end
-        ImGui.end_table
       end
-      ImGui.end
     end
   end
 
   private def render_palettes_tab_item : Nil
-    pram = @emu.ppu.pram.to_unsafe.as(UInt16*)
-    flags = ImGui::ImGuiColorEditFlags::NoAlpha | ImGui::ImGuiColorEditFlags::NoPicker |
-            ImGui::ImGuiColorEditFlags::NoOptions | ImGui::ImGuiColorEditFlags::NoInputs |
-            ImGui::ImGuiColorEditFlags::NoLabel | ImGui::ImGuiColorEditFlags::NoSidePreview |
-            ImGui::ImGuiColorEditFlags::NoDragDrop | ImGui::ImGuiColorEditFlags::NoBorder
-    with_style(ImGui::ImGuiStyleVar::ItemSpacing, ImGui::ImVec2.new(0, 0)) do
-      2.times do |idx|
-        group do
-          16.times do |palette_row|
-            16.times do |palette_col|
-              color = (pram + 0x100 * idx)[palette_row * 16 + palette_col]
-              rgb = ImGui::ImVec4.new((color & 0x1F) / 0x1F, (color >> 5 & 0x1F) / 0x1F, (color >> 10 & 0x1F) / 0x1F, 1)
-              ImGui.color_button("", rgb, flags, ImGui::ImVec2.new(10, 10))
-              ImGui.same_line unless palette_col == 15
+    ImGui.tab_item("Palettes") do
+      pram = @emu.ppu.pram.to_unsafe.as(UInt16*)
+      flags = ImGui::ImGuiColorEditFlags::NoAlpha | ImGui::ImGuiColorEditFlags::NoPicker |
+              ImGui::ImGuiColorEditFlags::NoOptions | ImGui::ImGuiColorEditFlags::NoInputs |
+              ImGui::ImGuiColorEditFlags::NoLabel | ImGui::ImGuiColorEditFlags::NoSidePreview |
+              ImGui::ImGuiColorEditFlags::NoDragDrop | ImGui::ImGuiColorEditFlags::NoBorder
+      ImGui.with_style_var(ImGui::ImGuiStyleVar::ItemSpacing, ImGui::ImVec2.new(0, 0)) do
+        2.times do |idx|
+          ImGui.group do
+            16.times do |palette_row|
+              16.times do |palette_col|
+                color = (pram + 0x100 * idx)[palette_row * 16 + palette_col]
+                rgb = ImGui::ImVec4.new((color & 0x1F) / 0x1F, (color >> 5 & 0x1F) / 0x1F, (color >> 10 & 0x1F) / 0x1F, 1)
+                ImGui.color_button("", rgb, flags, ImGui::ImVec2.new(10, 10))
+                ImGui.same_line unless palette_col == 15
+              end
             end
           end
+          ImGui.same_line(spacing: 4_f32) if idx == 0
         end
-        ImGui.same_line(spacing: 4_f32) if idx == 0
       end
     end
-    ImGui.end_tab_item
-  end
-
-  def group(&) : Nil
-    ImGui.begin_group
-    yield
-    ImGui.end_group
-  end
-
-  def child(*args, **kwargs, &) : Nil
-    if ImGui.begin_child(*args, **kwargs)
-      yield
-    end
-    ImGui.end_child
-  end
-
-  def with_style(*args, **kwargs, &) : Nil
-    ImGui.push_style_var(*args, **kwargs)
-    yield
-    ImGui.pop_style_var
   end
 end
diff --git a/src/crab/common/frontend/sdl_opengl_imgui_frontend.cr b/src/crab/common/frontend/sdl_opengl_imgui_frontend.cr
index e69e253..036db67 100644
--- a/src/crab/common/frontend/sdl_opengl_imgui_frontend.cr
+++ b/src/crab/common/frontend/sdl_opengl_imgui_frontend.cr
@@ -226,62 +226,56 @@ class SDLOpenGLImGuiFrontend < Frontend
     open_keybindings = false
 
     if show_menu_bar?
-      if ImGui.begin_main_menu_bar
-        if ImGui.begin_menu "File"
-          open_rom_selection = ImGui.menu_item "Open ROM"
-          open_bios_selection = ImGui.menu_item "Select BIOS" unless stubbed?
-          if ImGui.begin_menu "Recent", @config.recents.size > 0
-            @config.recents.each do |recent|
-              load_new_rom(recent) if ImGui.menu_item recent
-            end
-            ImGui.separator
-            if ImGui.menu_item "Clear"
-              @config.recents.clear
-              @config.commit
-            end
-            ImGui.end_menu
-          end
-          ImGui.separator
-          open_keybindings = ImGui.menu_item "Keybindings"
-          ImGui.separator
-          exit if ImGui.menu_item "Exit", "Ctrl+Q"
-          ImGui.end_menu
-        end
+      if ImGui.main_menu_bar do
+           ImGui.menu "File" do
+             open_rom_selection = ImGui.menu_item "Open ROM"
+             open_bios_selection = ImGui.menu_item "Select BIOS" unless stubbed?
+             ImGui.menu "Recent", @config.recents.size > 0 do
+               @config.recents.each do |recent|
+                 load_new_rom(recent) if ImGui.menu_item recent
+               end
+               ImGui.separator
+               if ImGui.menu_item "Clear"
+                 @config.recents.clear
+                 @config.commit
+               end
+             end
+             ImGui.separator
+             open_keybindings = ImGui.menu_item "Keybindings"
+             ImGui.separator
+             exit if ImGui.menu_item "Exit", "Ctrl+Q"
+           end
 
-        if ImGui.begin_menu "Emulation"
-          pause = @pause
+           ImGui.menu "Emulation" do
+             pause = @pause
 
-          ImGui.menu_item "Pause", "Ctrl+P", pointerof(pause)
-          @controller.toggle_sync if ImGui.menu_item "Audio Sync", "Tab", @controller.sync?, !stubbed?
+             ImGui.menu_item "Pause", "Ctrl+P", pointerof(pause)
+             @controller.toggle_sync if ImGui.menu_item "Audio Sync", "Tab", @controller.sync?, !stubbed?
 
-          pause(pause)
-          ImGui.end_menu
-        end
+             pause(pause)
+           end
 
-        if ImGui.begin_menu "Audio/Video"
-          if ImGui.begin_menu "Frame size"
-            (1..8).each do |scale|
-              if ImGui.menu_item "#{scale}x", selected: scale == @scale
-                @scale = scale
-                LibSDL.set_window_size(@window, @controller.window_width * @scale, @controller.window_height * @scale)
-              end
-            end
-            ImGui.separator
-            @window.fullscreen = @fullscreen if ImGui.menu_item "Fullscreen", "Ctrl+F", pointerof(@fullscreen)
-            ImGui.end_menu
-          end
-          ImGui.end_menu
-        end
+           ImGui.menu "Audio/Video" do
+             ImGui.menu "Frame size" do
+               (1..8).each do |scale|
+                 if ImGui.menu_item "#{scale}x", selected: scale == @scale
+                   @scale = scale
+                   LibSDL.set_window_size(@window, @controller.window_width * @scale, @controller.window_height * @scale)
+                 end
+               end
+               ImGui.separator
+               @window.fullscreen = @fullscreen if ImGui.menu_item "Fullscreen", "Ctrl+F", pointerof(@fullscreen)
+             end
+           end
 
-        if ImGui.begin_menu "Debug"
-          ImGui.menu_item "Overlay", "", pointerof(@enable_overlay)
-          ImGui.separator
-          @controller.render_debug_items
-          ImGui.end_menu
-        end
+           ImGui.menu "Debug" do
+             ImGui.menu_item "Overlay", "", pointerof(@enable_overlay)
+             ImGui.separator
+             @controller.render_debug_items
+           end
 
-        overlay_height += ImGui.get_window_size.y
-        ImGui.end_main_menu_bar
+           overlay_height += ImGui.get_window_size.y
+         end
       end
     end
 
@@ -293,17 +287,17 @@ class SDLOpenGLImGuiFrontend < Frontend
     if @enable_overlay
       ImGui.set_next_window_pos(ImGui::ImVec2.new 10, overlay_height)
       ImGui.set_next_window_bg_alpha(0.5)
-      ImGui.begin("Overlay", pointerof(@enable_overlay),
+      ImGui.window("Overlay", pointerof(@enable_overlay),
         ImGui::ImGuiWindowFlags::NoDecoration | ImGui::ImGuiWindowFlags::NoMove |
-        ImGui::ImGuiWindowFlags::NoSavedSettings)
-      io_framerate = @io.framerate
-      ImGui.text("FPS:        #{io_framerate.format(decimal_places: 1)}")
-      ImGui.text("Frame time: #{(1000 / io_framerate).format(decimal_places: 3)}ms")
-      ImGui.separator
-      ImGui.text("OpenGL")
-      ImGui.text("  Version: #{@opengl_info.version}")
-      ImGui.text("  Shading: #{@opengl_info.shading}")
-      ImGui.end
+        ImGui::ImGuiWindowFlags::NoSavedSettings) do
+        io_framerate = @io.framerate
+        ImGui.text("FPS:        #{io_framerate.format(decimal_places: 1)}")
+        ImGui.text("Frame time: #{(1000 / io_framerate).format(decimal_places: 3)}ms")
+        ImGui.separator
+        ImGui.text("OpenGL")
+        ImGui.text("  Version: #{@opengl_info.version}")
+        ImGui.text("  Shading: #{@opengl_info.shading}")
+      end
     end
 
     @controller.render_windows
diff --git a/src/crab/common/frontend/widgets/file_explorer.cr b/src/crab/common/frontend/widgets/file_explorer.cr
index 151ec46..353fcb9 100644
--- a/src/crab/common/frontend/widgets/file_explorer.cr
+++ b/src/crab/common/frontend/widgets/file_explorer.cr
@@ -22,7 +22,7 @@ module ImGui
       ImGui.open_popup(name.to_s) if open_popup
       center = ImGui.get_main_viewport.get_center
       ImGui.set_next_window_pos(center, ImGui::ImGuiCond::Appearing, ImGui::ImVec2.new(0.5, 0.5))
-      if ImGui.begin_popup_modal(name.to_s, flags: ImGui::ImGuiWindowFlags::AlwaysAutoResize)
+      ImGui.popup_modal(name.to_s, flags: ImGui::ImGuiWindowFlags::AlwaysAutoResize) do
         parts = @config.explorer_dir.parts
         parts.each_with_index do |part, idx|
           ImGui.same_line unless idx == 0
@@ -31,7 +31,7 @@ module ImGui
         display_size = ImGui.get_main_viewport.size
         width = Math.min(display_size.x - 40, 600)
         height = Math.min(display_size.y - 40, 16 * ImGui.get_text_line_height_with_spacing)
-        if ImGui.begin_list_box("##files", ImGui::ImVec2.new(width, height))
+        ImGui.list_box("##files", ImGui::ImVec2.new(width, height)) do
           @matched_entries.each_with_index do |entry, idx|
             next if entry[:hidden] && !@match_hidden
             next if entry[:file?] && !extensions.nil? && !extensions.includes?(entry[:extension])
@@ -53,16 +53,14 @@ module ImGui
             end
             ImGui.set_item_default_focus if is_selected
           end
-          ImGui.end_list_box
         end
-        ImGui.begin_group
-        open_file(name) if ImGui.button "Open"
-        ImGui.same_line
-        close if ImGui.button "Cancel"
-        ImGui.same_line(spacing: 10)
-        ImGui.checkbox("Show hidden files?", pointerof(@match_hidden))
-        ImGui.end_group
-        ImGui.end_popup
+        ImGui.group do
+          open_file(name) if ImGui.button "Open"
+          ImGui.same_line
+          close if ImGui.button "Cancel"
+          ImGui.same_line(spacing: 10)
+          ImGui.checkbox("Show hidden files?", pointerof(@match_hidden))
+        end
       end
     end
 
diff --git a/src/crab/common/frontend/widgets/keybindings.cr b/src/crab/common/frontend/widgets/keybindings.cr
index fa73507..14a212d 100644
--- a/src/crab/common/frontend/widgets/keybindings.cr
+++ b/src/crab/common/frontend/widgets/keybindings.cr
@@ -41,7 +41,7 @@ module ImGui
       center = ImGui.get_main_viewport.get_center
       ImGui.set_next_window_pos(center, ImGui::ImGuiCond::Appearing, ImGui::ImVec2.new(0.5, 0.5))
       hovered_button_color = ImGui.get_style_color_vec4(ImGui::ImGuiCol::ButtonHovered)
-      if ImGui.begin_popup_modal(POPUP_NAME, flags: ImGui::ImGuiWindowFlags::AlwaysAutoResize)
+      ImGui.popup_modal(POPUP_NAME, flags: ImGui::ImGuiWindowFlags::AlwaysAutoResize) do
         Input.each do |input|
           selected = @selection == input
           keycode = @editing_keycodes.key_for?(input)
@@ -58,7 +58,6 @@ module ImGui
         apply if ImGui.button "Apply"
         ImGui.same_line
         close if ImGui.button "Cancel"
-        ImGui.end_popup
       end
     end