diff --git a/lv_core/lv_obj.c b/lv_core/lv_obj.c
index 77f9958dd..6c791a6eb 100644
--- a/lv_core/lv_obj.c
+++ b/lv_core/lv_obj.c
@@ -364,7 +364,7 @@ void lv_obj_invalidate(lv_obj_t * obj)
 
         /*Check through all parents*/
         while(par != NULL) {
-            union_ok = lv_area_union(&area_trunc, &area_trunc, &par->coords);
+            union_ok = lv_area_intersect(&area_trunc, &area_trunc, &par->coords);
             if(union_ok == false) break;        /*If no common parts with parent break;*/
             if(lv_obj_get_hidden(par)) return;  /*If the parent is hidden then the child is hidden and won't be drawn*/
 
diff --git a/lv_core/lv_refr.c b/lv_core/lv_refr.c
index fbf14d8f9..8b0ea59d9 100644
--- a/lv_core/lv_refr.c
+++ b/lv_core/lv_refr.c
@@ -93,7 +93,7 @@ void lv_inv_area(const lv_area_t * area_p)
     lv_area_t com_area;
     bool suc;
 
-    suc = lv_area_union(&com_area, area_p, &scr_area);
+    suc = lv_area_intersect(&com_area, area_p, &scr_area);
 
     /*The area is truncated to the screen*/
     if(suc != false) {
@@ -328,7 +328,7 @@ static void lv_refr_area_part_vdb(const lv_area_t * area_p)
     /*Get the new mask from the original area and the act. VDB
      It will be a part of 'area_p'*/
     lv_area_t start_mask;
-    lv_area_union(&start_mask, area_p, &vdb_p->area);
+    lv_area_intersect(&start_mask, area_p, &vdb_p->area);
 
     /*Get the most top object which is not covered by others*/
     top_p = lv_refr_get_top_obj(&start_mask, lv_scr_act());
@@ -451,7 +451,7 @@ static void lv_refr_obj(lv_obj_t * obj, const lv_area_t * mask_ori_p)
     obj_area.y1 -= ext_size;
     obj_area.x2 += ext_size;
     obj_area.y2 += ext_size;
-    union_ok = lv_area_union(&obj_ext_mask, mask_ori_p, &obj_area);
+    union_ok = lv_area_intersect(&obj_ext_mask, mask_ori_p, &obj_area);
 
     /*Draw the parent and its children only if they ore on 'mask_parent'*/
     if(union_ok != false) {
@@ -465,7 +465,7 @@ static void lv_refr_obj(lv_obj_t * obj, const lv_area_t * mask_ori_p)
 
         /*Create a new 'obj_mask' without 'ext_size' because the children can't be visible there*/
         lv_obj_get_coords(obj, &obj_area);
-        union_ok = lv_area_union(&obj_mask, mask_ori_p, &obj_area);
+        union_ok = lv_area_intersect(&obj_mask, mask_ori_p, &obj_area);
         if(union_ok != false) {
             lv_area_t mask_child; /*Mask from obj and its child*/
             lv_obj_t * child_p;
@@ -479,7 +479,7 @@ static void lv_refr_obj(lv_obj_t * obj, const lv_area_t * mask_ori_p)
                 child_area.y2 += ext_size;
                 /* Get the union (common parts) of original mask (from obj)
                  * and its child */
-                union_ok = lv_area_union(&mask_child, &obj_mask, &child_area);
+                union_ok = lv_area_intersect(&mask_child, &obj_mask, &child_area);
 
                 /*If the parent and the child has common area then refresh the child */
                 if(union_ok) {
diff --git a/lv_draw/lv_draw.c b/lv_draw/lv_draw.c
index 534e5139b..284fac825 100644
--- a/lv_draw/lv_draw.c
+++ b/lv_draw/lv_draw.c
@@ -431,7 +431,7 @@ void lv_draw_img(const lv_area_t * coords, const lv_area_t * mask,
 
             lv_area_t mask_com;    /*Common area of mask and cords*/
             bool union_ok;
-            union_ok = lv_area_union(&mask_com, mask, coords);
+            union_ok = lv_area_intersect(&mask_com, mask, coords);
             if(union_ok == false) {
                 lv_fs_close(&file);
                 return;
@@ -506,7 +506,7 @@ void lv_draw_img(const lv_area_t * coords, const lv_area_t * mask,
         const lv_img_t * img_var = src;
         lv_area_t mask_com;    /*Common area of mask and coords*/
         bool union_ok;
-        union_ok = lv_area_union(&mask_com, mask, coords);
+        union_ok = lv_area_intersect(&mask_com, mask, coords);
         if(union_ok == false) {
             return;         /*Out of mask*/
         }
diff --git a/lv_draw/lv_draw_rbasic.c b/lv_draw/lv_draw_rbasic.c
index ef9996685..369adf523 100644
--- a/lv_draw/lv_draw_rbasic.c
+++ b/lv_draw/lv_draw_rbasic.c
@@ -76,11 +76,11 @@ void lv_rfill(const lv_area_t * cords_p, const lv_area_t * mask_p,
     bool union_ok = true;
 
     if(mask_p != NULL) {
-        union_ok = lv_area_union(&masked_area, cords_p, mask_p);
+        union_ok = lv_area_intersect(&masked_area, cords_p, mask_p);
     } else {
         lv_area_t scr_area;
         lv_area_set(&scr_area, 0, 0, LV_HOR_RES - 1, LV_VER_RES - 1);
-        union_ok = lv_area_union(&masked_area, cords_p, &scr_area);
+        union_ok = lv_area_intersect(&masked_area, cords_p, &scr_area);
     }
 
     if(union_ok != false) {
@@ -222,7 +222,7 @@ void lv_rmap(const lv_area_t * cords_p, const lv_area_t * mask_p,
     lv_area_t masked_a;
     bool union_ok;
 
-    union_ok = lv_area_union(&masked_a, cords_p, mask_p);
+    union_ok = lv_area_intersect(&masked_a, cords_p, mask_p);
 
     /*If there are common part of the mask and map then draw the map*/
     if(union_ok == false) return;
diff --git a/lv_draw/lv_draw_vbasic.c b/lv_draw/lv_draw_vbasic.c
index 1f2033267..a71c06c27 100644
--- a/lv_draw/lv_draw_vbasic.c
+++ b/lv_draw/lv_draw_vbasic.c
@@ -101,7 +101,7 @@ void lv_vfill(const lv_area_t * cords_p, const lv_area_t * mask_p,
     /*Get the union of cord and mask*/
     /* The mask is already truncated to the vdb size
      * in 'lv_refr_area_with_vdb' function */
-    union_ok = lv_area_union(&res_a, cords_p, mask_p);
+    union_ok = lv_area_intersect(&res_a, cords_p, mask_p);
 
     /*If there are common part of the three area then draw to the vdb*/
     if(union_ok == false) return;
@@ -337,7 +337,7 @@ void lv_vmap(const lv_area_t * cords_p, const lv_area_t * mask_p,
     /*Get the union of map size and mask*/
     /* The mask is already truncated to the vdb size
     * in 'lv_refr_area_with_vdb' function */
-    union_ok = lv_area_union(&masked_a, cords_p, mask_p);
+    union_ok = lv_area_intersect(&masked_a, cords_p, mask_p);
 
     /*If there are common part of the three area then draw to the vdb*/
     if(union_ok == false)  return;
diff --git a/lv_misc/lv_area.c b/lv_misc/lv_area.c
index 3ba5d303a..f340690a4 100644
--- a/lv_misc/lv_area.c
+++ b/lv_misc/lv_area.c
@@ -102,12 +102,12 @@ uint32_t lv_area_get_size(const lv_area_t * area_p)
 
 /**
  * Get the common parts of two areas
- * @param res_p pointer to an area, the result will be stored her
+ * @param res_p pointer to an area, the result will be stored here
  * @param a1_p pointer to the first area
  * @param a2_p pointer to the second area
  * @return false: the two area has NO common parts, res_p is invalid
  */
-bool lv_area_union(lv_area_t * res_p, const lv_area_t * a1_p, const lv_area_t * a2_p)
+bool lv_area_intersect(lv_area_t * res_p, const lv_area_t * a1_p, const lv_area_t * a2_p)
 {
     /* Get the smaller area from 'a1_p' and 'a2_p' */
     res_p->x1 = LV_MATH_MAX(a1_p->x1, a2_p->x1);
diff --git a/lv_misc/lv_area.h b/lv_misc/lv_area.h
index 4663e0106..fc8b7dec8 100644
--- a/lv_misc/lv_area.h
+++ b/lv_misc/lv_area.h
@@ -123,7 +123,7 @@ uint32_t lv_area_get_size(const lv_area_t * area_p);
  * @param a2_p pointer to the second area
  * @return false: the two area has NO common parts, res_p is invalid
  */
-bool lv_area_union(lv_area_t * res_p, const lv_area_t * a1_p, const lv_area_t * a2_p);
+bool lv_area_intersect(lv_area_t * res_p, const lv_area_t * a1_p, const lv_area_t * a2_p);
 
 /**
  * Join two areas into a third which involves the other two
diff --git a/lv_objx/lv_chart.c b/lv_objx/lv_chart.c
index b32caaa37..fac54ad08 100644
--- a/lv_objx/lv_chart.c
+++ b/lv_objx/lv_chart.c
@@ -670,7 +670,7 @@ static void lv_chart_draw_cols(lv_obj_t * chart, const lv_area_t * mask)
             y_tmp = y_tmp / (ext->ymax - ext->ymin);
             col_a.y1 = h - y_tmp + chart->coords.y1;
 
-            mask_ret = lv_area_union(&col_mask, mask, &col_a);
+            mask_ret = lv_area_intersect(&col_mask, mask, &col_a);
             if(mask_ret != false) {
                 lv_draw_rect(&chart->coords, &col_mask, &rects);
             }
diff --git a/lv_objx/lv_ddlist.c b/lv_objx/lv_ddlist.c
index 1d2687275..da10aa94f 100644
--- a/lv_objx/lv_ddlist.c
+++ b/lv_objx/lv_ddlist.c
@@ -479,7 +479,7 @@ static bool lv_ddlist_design(lv_obj_t * ddlist, const lv_area_t * mask, lv_desig
         area_sel.x2 = ddlist->coords.x2;
         lv_area_t mask_sel;
         bool area_ok;
-        area_ok = lv_area_union(&mask_sel, mask, &area_sel);
+        area_ok = lv_area_intersect(&mask_sel, mask, &area_sel);
         if(area_ok) {
             lv_style_t * sel_style = lv_ddlist_get_style(ddlist, LV_DDLIST_STYLE_SEL);
             lv_style_t new_style;
diff --git a/lv_objx/lv_roller.c b/lv_objx/lv_roller.c
index 3c3a909f0..5b4092586 100644
--- a/lv_objx/lv_roller.c
+++ b/lv_objx/lv_roller.c
@@ -251,7 +251,7 @@ static bool lv_roller_design(lv_obj_t * roller, const lv_area_t * mask, lv_desig
         rect_area.x2 = roller->coords.x2;
         lv_area_t mask_sel;
         bool area_ok;
-        area_ok = lv_area_union(&mask_sel, mask, &rect_area);
+        area_ok = lv_area_intersect(&mask_sel, mask, &rect_area);
         if(area_ok) {
             lv_style_t * sel_style = lv_roller_get_style(roller, LV_ROLLER_STYLE_SEL);
             lv_style_t new_style;
@@ -416,7 +416,7 @@ static void draw_bg(lv_obj_t * roller, const lv_area_t * mask)
     half_roller.y1 -= roller->ext_size;
     half_roller.y2 = roller->coords.y1 + h / 2;
 
-    union_ok = lv_area_union(&half_mask, &half_roller, mask);
+    union_ok = lv_area_intersect(&half_mask, &half_roller, mask);
 
     half_roller.x1 += roller->ext_size; /*Revert ext. size adding*/
     half_roller.x2 -= roller->ext_size;
@@ -433,7 +433,7 @@ static void draw_bg(lv_obj_t * roller, const lv_area_t * mask)
     half_roller.y1 = roller->coords.y1 + h / 2;
     if((h & 0x1) == 0) half_roller.y1++;    /*With even height the pixels in the middle would be drawn twice*/
 
-    union_ok = lv_area_union(&half_mask, &half_roller, mask);
+    union_ok = lv_area_intersect(&half_mask, &half_roller, mask);
 
     half_roller.x1 += roller->ext_size; /*Revert ext. size adding*/
     half_roller.x2 -= roller->ext_size;