diff --git a/components/partition_table/test/test_partition.c b/components/partition_table/test/test_partition.c
index 64ead9692c..5267b5bac7 100644
--- a/components/partition_table/test/test_partition.c
+++ b/components/partition_table/test/test_partition.c
@@ -73,7 +73,7 @@ TEST_CASE("Can write, read, mmap partition", "[partition][ignore]")
     const uint32_t *mmap_data;
     spi_flash_mmap_handle_t mmap_handle;
     size_t begin = 3000;
-    size_t size = 12000;
+    size_t size = 64000; //chosen so size is smaller than 64K but the mmap straddles 2 MMU blocks
     TEST_ASSERT_EQUAL(ESP_OK, esp_partition_mmap(p, begin, size, SPI_FLASH_MMAP_DATA,
                       (const void **)&mmap_data, &mmap_handle));
     srand(0);
diff --git a/components/spi_flash/partition.c b/components/spi_flash/partition.c
index 94d6ff6a66..1c3ac610fa 100644
--- a/components/spi_flash/partition.c
+++ b/components/spi_flash/partition.c
@@ -315,7 +315,7 @@ esp_err_t esp_partition_mmap(const esp_partition_t* partition, uint32_t offset,
     // offset within 64kB block
     size_t region_offset = phys_addr & 0xffff;
     size_t mmap_addr = phys_addr & 0xffff0000;
-    esp_err_t rc = spi_flash_mmap(mmap_addr, size, memory, out_ptr, out_handle);
+    esp_err_t rc = spi_flash_mmap(mmap_addr, size+region_offset, memory, out_ptr, out_handle);
     // adjust returned pointer to point to the correct offset
     if (rc == ESP_OK) {
         *out_ptr = (void*) (((ptrdiff_t) *out_ptr) + region_offset);