diff --git a/lv_themes/lv_theme.c b/lv_themes/lv_theme.c
index bbdca6e4c..4b76c8b78 100644
--- a/lv_themes/lv_theme.c
+++ b/lv_themes/lv_theme.c
@@ -35,7 +35,7 @@ static lv_theme_t * current_theme;
  * (The pointers in the theme points to the styles declared by the theme itself) */
 
 /* Store the styles in this array. */
-static lv_style_t th_styles[sizeof(((lv_theme_t *)0)->style) / sizeof(lv_style_t *)];
+static lv_style_t th_styles[LV_THEME_STYLE_COUNT];
 static bool inited = false;
 static lv_theme_t current_theme;
 #endif
diff --git a/lv_themes/lv_theme.h b/lv_themes/lv_theme.h
index cdb0771f8..24db3d5e6 100644
--- a/lv_themes/lv_theme.h
+++ b/lv_themes/lv_theme.h
@@ -314,6 +314,9 @@ lv_theme_t * lv_theme_get_current(void);
  *    MACROS
  **********************/
 
+/* Returns number of styles within the `lv_theme_t` structure. */
+#define LV_THEME_STYLE_COUNT    (sizeof(((lv_theme_t *)0)->style) / sizeof(lv_style_t *))
+
 /**********************
  *     POST INCLUDE
  *********************/
diff --git a/lv_themes/lv_theme_alien.c b/lv_themes/lv_theme_alien.c
index 8b5f469a9..c3dc48dac 100644
--- a/lv_themes/lv_theme_alien.c
+++ b/lv_themes/lv_theme_alien.c
@@ -817,8 +817,8 @@ lv_theme_t * lv_theme_alien_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }
diff --git a/lv_themes/lv_theme_default.c b/lv_themes/lv_theme_default.c
index 9a972571a..f16e47a9d 100644
--- a/lv_themes/lv_theme_default.c
+++ b/lv_themes/lv_theme_default.c
@@ -376,8 +376,8 @@ lv_theme_t * lv_theme_default_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }
diff --git a/lv_themes/lv_theme_material.c b/lv_themes/lv_theme_material.c
index 6cfe50104..e5d5d5d42 100644
--- a/lv_themes/lv_theme_material.c
+++ b/lv_themes/lv_theme_material.c
@@ -801,8 +801,8 @@ lv_theme_t * lv_theme_material_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }
diff --git a/lv_themes/lv_theme_mono.c b/lv_themes/lv_theme_mono.c
index 44c02754f..babfc4998 100644
--- a/lv_themes/lv_theme_mono.c
+++ b/lv_themes/lv_theme_mono.c
@@ -435,8 +435,8 @@ lv_theme_t * lv_theme_mono_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }
diff --git a/lv_themes/lv_theme_nemo.c b/lv_themes/lv_theme_nemo.c
index 339682ad2..c10fc303f 100644
--- a/lv_themes/lv_theme_nemo.c
+++ b/lv_themes/lv_theme_nemo.c
@@ -800,8 +800,8 @@ lv_theme_t * lv_theme_nemo_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }
diff --git a/lv_themes/lv_theme_night.c b/lv_themes/lv_theme_night.c
index 4f86bd032..c65efba97 100644
--- a/lv_themes/lv_theme_night.c
+++ b/lv_themes/lv_theme_night.c
@@ -710,8 +710,8 @@ lv_theme_t * lv_theme_night_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }
diff --git a/lv_themes/lv_theme_templ.c b/lv_themes/lv_theme_templ.c
index eb2e0747c..906ec52a2 100644
--- a/lv_themes/lv_theme_templ.c
+++ b/lv_themes/lv_theme_templ.c
@@ -385,8 +385,8 @@ lv_theme_t * lv_theme_templ_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }
diff --git a/lv_themes/lv_theme_zen.c b/lv_themes/lv_theme_zen.c
index f04be7bcc..3f3f29923 100644
--- a/lv_themes/lv_theme_zen.c
+++ b/lv_themes/lv_theme_zen.c
@@ -767,8 +767,8 @@ lv_theme_t * lv_theme_zen_init(uint16_t hue, lv_font_t * font)
 
     /*For backward compatibility initialize all theme elements with a default style */
     uint16_t i;
-    lv_style_t ** style_p = (lv_style_t **) &theme;
-    for(i = 0; i < sizeof(lv_theme_t) / sizeof(lv_style_t *); i++) {
+    lv_style_t ** style_p = (lv_style_t **) &theme.style;
+    for(i = 0; i < LV_THEME_STYLE_COUNT; i++) {
         *style_p = &def;
         style_p++;
     }