diff --git a/src/hello_imgui/internal/docking_details.cpp b/src/hello_imgui/internal/docking_details.cpp
index 581272d1..2f83c135 100644
--- a/src/hello_imgui/internal/docking_details.cpp
+++ b/src/hello_imgui/internal/docking_details.cpp
@@ -345,7 +345,7 @@ ImRect FixedWindowRect(
                 if ( edgeToolbarType == EdgeToolbarType::Left)
                 {
                     auto width = HelloImGui::EmSize(
-                        runnerParams.callbacks.edgesToolbars.at(EdgeToolbarType::Right).options.sizeEm);
+                        runnerParams.callbacks.edgesToolbars.at(EdgeToolbarType::Left).options.sizeEm);
                     fullScreenSize.x = width;
                 }
                 if ( edgeToolbarType == EdgeToolbarType::Right)
@@ -578,4 +578,4 @@ std::optional<ImGuiID> DockingParams::dockSpaceIdFromName(const std::string& doc
 }
 
 
-}  // namespace HelloImGui
\ No newline at end of file
+}  // namespace HelloImGui