diff --git a/components/heap/heap_caps_init.c b/components/heap/heap_caps_init.c
index 75556dd155..5a7beb3a7c 100644
--- a/components/heap/heap_caps_init.c
+++ b/components/heap/heap_caps_init.c
@@ -189,14 +189,14 @@ bool heap_caps_check_add_region_allowed(intptr_t heap_start, intptr_t heap_end,
      *  3.add region  (s3>=s && e3<e)                             |---------------|                      correct: bool condition_3 = start >= heap_start && end < heap_end;
      *                                                                  |--------------|                 correct
      *
-     *  4.add region  (s4<e && e4>e)                              |------------------------|             wrong:   bool condition_4 = start < heap_end && end > heap_end;
+     *  4.add region  (s4<e && e4>=e)                              |------------------------|            wrong:   bool condition_4 = start < heap_end && end >= heap_end;
      *                                                                  |---------------------|          wrong
      *
      *  5.add region  (s5>=e)                                                            |----|          correct: bool condition_5 = start >= heap_end;
      */
 
     bool condition_2 = start < heap_start && end > heap_start;        // if true then region not allowed
-    bool condition_4 = start < heap_end && end > heap_end;            // if true then region not allowed
+    bool condition_4 = start < heap_end && end >= heap_end;            // if true then region not allowed
 
     return (condition_2 || condition_4) ? false: true;
 }
diff --git a/components/heap/test_apps/main/test_runtime_heap_reg.c b/components/heap/test_apps/main/test_runtime_heap_reg.c
index 2dd56a1f93..8e54973ede 100644
--- a/components/heap/test_apps/main/test_runtime_heap_reg.c
+++ b/components/heap/test_apps/main/test_runtime_heap_reg.c
@@ -87,6 +87,9 @@ TEST_CASE("Add .bss memory to heap region runtime", "[heap]")
     printf("Before %"PRIu32" after %"PRIu32"\n", before_free, after_free);
     /* allow for some 'heap overhead' from accounting structures */
     TEST_ASSERT(after_free >= before_free + BUF_SZ - HEAP_OVERHEAD_MAX);
+
+    /* Twice add must be failed */
+    TEST_ASSERT( (heap_caps_add_region((intptr_t)s_buffer, (intptr_t)s_buffer + BUF_SZ) != ESP_OK) );
 }
 
 extern esp_err_t heap_caps_check_add_region_allowed(intptr_t heap_start, intptr_t heap_end, intptr_t start, intptr_t end);
@@ -98,10 +101,10 @@ TEST_CASE("Add heap region address range checks", "[heap]")
 
     TEST_ASSERT_TRUE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x0, 0x1000));
     TEST_ASSERT_TRUE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x1000, 0x2000));
-    TEST_ASSERT_TRUE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x1000, 0x3000));
     TEST_ASSERT_TRUE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x3000, 0x4000));
     TEST_ASSERT_FALSE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x0, 0x2000));
     TEST_ASSERT_FALSE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x0, 0x4000));
     TEST_ASSERT_FALSE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x1000, 0x4000));
     TEST_ASSERT_FALSE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x2000, 0x4000));
+    TEST_ASSERT_FALSE(heap_caps_check_add_region_allowed(heap_start, heap_end, 0x1000, 0x3000));
 }