diff --git a/kitty/border_vertex.glsl b/kitty/border_vertex.glsl
index c394d8b86..4a74b50b2 100644
--- a/kitty/border_vertex.glsl
+++ b/kitty/border_vertex.glsl
@@ -1,5 +1,6 @@
 uniform uvec2 viewport;
 uniform uint colors[9];
+uniform float background_opacity;
 uniform float tint_opacity, tint_premult;
 uniform float gamma_lut[256];
 in vec4 rect;  // left, top, right, bottom
@@ -41,7 +42,7 @@ void main() {
     float is_window_bg = is_integer_value(rc, 3.);
     float is_default_bg = is_integer_value(rc, 0.);
     color3 = is_window_bg * window_bg + (1. - is_window_bg) * color3;
-    float final_opacity = is_default_bg * tint_opacity + (1. - is_default_bg);
-    float final_premult_opacity = is_default_bg * tint_premult + (1. - is_default_bg);
+    float final_opacity = is_default_bg * tint_opacity + (1. - is_default_bg) * background_opacity;
+    float final_premult_opacity = is_default_bg * tint_premult + (1. - is_default_bg) * background_opacity;
     color = vec4(color3 * final_premult_opacity, final_opacity);
 }
diff --git a/kitty/shaders.c b/kitty/shaders.c
index ce96576a8..92957b674 100644
--- a/kitty/shaders.c
+++ b/kitty/shaders.c
@@ -1087,13 +1087,15 @@ create_border_vao(void) {
 
 void
 draw_borders(ssize_t vao_idx, unsigned int num_border_rects, BorderRect *rect_buf, bool rect_data_is_dirty, uint32_t viewport_width, uint32_t viewport_height, color_type active_window_bg, unsigned int num_visible_windows, bool all_windows_have_same_bg, OSWindow *w) {
-    float tint_opacity = w->is_semi_transparent ? w->background_opacity: 1.0f;
-    float tint_premult = tint_opacity;
+    float background_opacity = w->is_semi_transparent ? w->background_opacity: 1.0f;
+    float tint_opacity = background_opacity;
+    float tint_premult = background_opacity;
     if (has_bgimage(w)) {
         glEnable(GL_BLEND);
         BLEND_ONTO_OPAQUE;
         draw_background_image(w);
         BLEND_ONTO_OPAQUE;
+        background_opacity = 1.0f;
         tint_opacity = OPT(background_tint) * OPT(background_tint_gaps);
         tint_premult = w->is_semi_transparent ? OPT(background_tint) : 1.0f;
     }
@@ -1114,6 +1116,7 @@ draw_borders(ssize_t vao_idx, unsigned int num_border_rects, BorderRect *rect_bu
             w->tab_bar_edge_color.left, w->tab_bar_edge_color.right
         };
         glUniform1uiv(border_program_layout.uniforms.colors, arraysz(colors), colors);
+        glUniform1f(border_program_layout.uniforms.background_opacity, background_opacity);
         glUniform1f(border_program_layout.uniforms.tint_opacity, tint_opacity);
         glUniform1f(border_program_layout.uniforms.tint_premult, tint_premult);
         glUniform2ui(border_program_layout.uniforms.viewport, viewport_width, viewport_height);