diff --git a/src/widgets/dropdown/lv_dropdown.c b/src/widgets/dropdown/lv_dropdown.c
index ea93be3a4c..da18176283 100644
--- a/src/widgets/dropdown/lv_dropdown.c
+++ b/src/widgets/dropdown/lv_dropdown.c
@@ -404,11 +404,13 @@ int32_t lv_dropdown_get_option_index(lv_obj_t * obj, const char * option)
     uint32_t char_i = 0;
     uint32_t opt_i = 0;
     const char * start = opts;
+    const size_t option_len = lv_strlen(option); /*avoid recomputing this multiple times in the loop*/
 
     while(start[0] != '\0') {
         for(char_i = 0; (start[char_i] != '\n') && (start[char_i] != '\0'); char_i++);
 
-        if(memcmp(start, option, LV_MIN(lv_strlen(option), char_i)) == 0) return opt_i;
+        if(option_len == char_i &&
+           memcmp(start, option, option_len) == 0) return opt_i; /*cannot match exactly unless they are the same length*/
         start = &start[char_i];
         if(start[0] == '\n') start++;
         opt_i++;
diff --git a/tests/src/test_cases/test_dropdown.c b/tests/src/test_cases/test_dropdown.c
index a1c30b1a06..546be0da30 100644
--- a/tests/src/test_cases/test_dropdown.c
+++ b/tests/src/test_cases/test_dropdown.c
@@ -441,5 +441,17 @@ void test_dropdown_should_list_on_top(void)
     TEST_ASSERT_EQUAL_INT(2, lv_obj_get_index(list));
 }
 
+/* See #4191 */
+void test_dropdown_get_options_should_check_lengths(void)
+{
+    lv_obj_t * dd = lv_dropdown_create(lv_scr_act());
+    lv_dropdown_set_options(dd, "abc\nab");
+    TEST_ASSERT_EQUAL_INT(1, lv_dropdown_get_option_index(dd, "ab"));
+
+    lv_dropdown_set_options(dd, "Option 1\nOption 2\nOption 3\nOption");
+    TEST_ASSERT_EQUAL_INT(3, lv_dropdown_get_option_index(dd, "Option"));
+    TEST_ASSERT_EQUAL_INT(-1, lv_dropdown_get_option_index(dd, "Option "));
+}
+
 
 #endif