diff --git a/components/wear_levelling/WL_Flash.cpp b/components/wear_levelling/WL_Flash.cpp
index 92050daef9b..f5d58d884e0 100644
--- a/components/wear_levelling/WL_Flash.cpp
+++ b/components/wear_levelling/WL_Flash.cpp
@@ -577,6 +577,13 @@ esp_err_t WL_Flash::write(size_t dest_addr, const void *src, size_t size)
     if (!this->initialized) {
         return ESP_ERR_INVALID_STATE;
     }
+    if (size == 0) {
+        // Nothing to do. Guard this explicitly: size is unsigned, so
+        // `size - 1` below would otherwise wrap around to SIZE_MAX and turn
+        // "count" into a huge page count, walking far past the caller's
+        // buffer (see components/wear_levelling/host_test).
+        return ESP_OK;
+    }
     ESP_LOGD(TAG, "%s - dest_addr= 0x%08" PRIx32 ", size= 0x%08" PRIx32 , __func__, (uint32_t) dest_addr, (uint32_t) size);
     uint32_t count = (size - 1) / this->cfg.wl_page_size;
     for (size_t i = 0; i < count; i++) {
@@ -596,6 +603,11 @@ esp_err_t WL_Flash::read(size_t src_addr, void *dest, size_t size)
     if (!this->initialized) {
         return ESP_ERR_INVALID_STATE;
     }
+    if (size == 0) {
+        // See the matching guard in WL_Flash::write() above: size==0 must
+        // not be allowed to reach the `size - 1` computation below.
+        return ESP_OK;
+    }
     ESP_LOGD(TAG, "%s - src_addr= 0x%08" PRIx32 ", size= 0x%08" PRIx32 , __func__, (uint32_t) src_addr, (uint32_t) size);
     uint32_t count = (size - 1) / this->cfg.wl_page_size;
     for (size_t i = 0; i < count; i++) {
diff --git a/components/wear_levelling/host_test/main/test_wl.cpp b/components/wear_levelling/host_test/main/test_wl.cpp
index 69ac2634f30..ce9819a8743 100644
--- a/components/wear_levelling/host_test/main/test_wl.cpp
+++ b/components/wear_levelling/host_test/main/test_wl.cpp
@@ -99,6 +99,39 @@ TEST_CASE("write and read back data", "[wear_levelling]")
     free(read);
 }
 
+TEST_CASE("write and read with zero size are safe no-ops", "[wear_levelling]")
+{
+    esp_err_t result;
+    wl_handle_t wl_handle;
+
+    const esp_partition_t *partition = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_ANY, "storage");
+
+    // Mount wear-levelled partition
+    result = wl_mount(partition, &wl_handle);
+    REQUIRE(result == ESP_OK);
+
+    // wl_write()/wl_read() do not document size==0 as invalid (analogous to
+    // POSIX write()/read() with count==0), so it must not be treated as an
+    // out-of-bounds request. Previously, WL_Flash::write()/read() computed
+    // `(size - 1) / wl_page_size` without checking for size==0 first; since
+    // size is unsigned, size==0 wrapped this to a huge page count and walked
+    // far past the caller-provided buffer.
+    uint8_t dummy = 0xAA;
+    result = wl_write(wl_handle, 0, &dummy, 0);
+    REQUIRE(result == ESP_OK);
+
+    uint8_t read_back = 0x55;
+    result = wl_read(wl_handle, 0, &read_back, 0);
+    REQUIRE(result == ESP_OK);
+
+    // Untouched by a genuine zero-length read.
+    REQUIRE(read_back == 0x55);
+
+    // Unmount
+    result = wl_unmount(wl_handle);
+    REQUIRE(result == ESP_OK);
+}
+
 TEST_CASE("power down test", "[wear_levelling]")
 {
     esp_err_t result;