diff --git a/particles/progress-bar.c b/particles/progress-bar.c
index 7011feb..ebc51c3 100644
--- a/particles/progress-bar.c
+++ b/particles/progress-bar.c
@@ -74,7 +74,7 @@ begin_expose(struct exposable *exposable)
 
     /* Margins */
     if (have_at_least_one) {
-        exposable->width = exposable->particle->left_margin +
+        exposable->width += exposable->particle->left_margin +
             exposable->particle->right_margin;
     } else
         assert(exposable->width == 0);