diff --git a/shaders/selection.frag.glsl b/shaders/selection.frag.glsl
index be04a82..83ce5dd 100644
--- a/shaders/selection.frag.glsl
+++ b/shaders/selection.frag.glsl
@@ -5,6 +5,7 @@ in vec2 vPos;
 out vec4 FragColor;
 
 uniform float uTime;
+uniform float uScale;
 uniform vec4 uColor1;
 uniform vec4 uColor2;
 uniform vec2 uMin;
@@ -12,7 +13,7 @@ uniform vec2 uMax;
 
 void main()
 {
-    float borderWidth = 0.008;
+    float borderWidth = 0.008 / uScale;
 
 
     float distX = min(vPos.x - uMin.x, uMax.x - vPos.x);
diff --git a/src/ui/vektorcanvas.c b/src/ui/vektorcanvas.c
index 2ac9a6a..4580251 100644
--- a/src/ui/vektorcanvas.c
+++ b/src/ui/vektorcanvas.c
@@ -38,6 +38,7 @@ static GLuint shader_standard_uProjMatrixLoc;
 
 static GLuint shader_selection_uProjMatrixLoc;
 static GLuint shader_selection_uTimeLoc;
+static GLuint shader_selection_uScaleLoc;
 static GLuint shader_selection_uC1Loc;
 static GLuint shader_selection_uC2Loc;
 static GLuint shader_selection_uMinLoc;
@@ -103,6 +104,8 @@ static void init_shader(void) {
         glGetUniformLocation(selection_shader_program, "uProjection");
     shader_selection_uTimeLoc =
         glGetUniformLocation(selection_shader_program, "uTime");
+    shader_selection_uScaleLoc =
+        glGetUniformLocation(selection_shader_program, "uScale");
     shader_selection_uC1Loc =
         glGetUniformLocation(selection_shader_program, "uColor1");
     shader_selection_uC2Loc =
@@ -205,6 +208,7 @@ static gboolean render(GtkGLArea* a, GdkGLContext* ctx,
         glUniformMatrix4fv(shader_selection_uProjMatrixLoc, 1, GL_FALSE,
                            renderInfo->canvasTransform);
         glUniform1f(shader_selection_uTimeLoc, time);
+        glUniform1f(shader_selection_uScaleLoc, renderInfo->zoom);
         glUniform2f(shader_selection_uMinLoc, bbox.min.x, bbox.min.y);
         glUniform2f(shader_selection_uMaxLoc, bbox.max.x, bbox.max.y);
         glUniform4f(shader_selection_uC1Loc, 0, 0, 0, 0);