diff --git a/01.curriculum/01.physics-chemistry-biology/03.Niv3/01.nature light/01.electromagnetic-spectrum/01.new-course-main/textbook.en.md b/01.curriculum/01.physics-chemistry-biology/03.Niv3/01.nature light/01.electromagnetic-spectrum/01.new-course-main/textbook.en.md
index aa2d82f6b..536ac28bf 100644
--- a/01.curriculum/01.physics-chemistry-biology/03.Niv3/01.nature light/01.electromagnetic-spectrum/01.new-course-main/textbook.en.md	
+++ b/01.curriculum/01.physics-chemistry-biology/03.Niv3/01.nature light/01.electromagnetic-spectrum/01.new-course-main/textbook.en.md	
@@ -6,4 +6,4 @@ published: no
 test :
 $`\oiint_S \vec{B} \cdot \vec{dS}`$
 
-$`\Longoiint_S \vec{B} \cdot \vec{dS}`$
\ No newline at end of file
+$`\Long\oiint_S \vec{B} \cdot \vec{dS}`$
\ No newline at end of file