diff --git a/components/spi_flash/test/test_esp_flash.c b/components/spi_flash/test/test_esp_flash.c
index 9fbeee9d86..73ae94554a 100644
--- a/components/spi_flash/test/test_esp_flash.c
+++ b/components/spi_flash/test/test_esp_flash.c
@@ -382,7 +382,8 @@ void test_simple_read_write(esp_flash_t *chip)
 
     srand(test_seed);
     for (int i = 0; i < sizeof(sector_buf); i++) {
-        TEST_ASSERT_EQUAL_HEX8(rand() & 0xFF, sector_buf[i]);
+        uint8_t data = rand();
+        TEST_ASSERT_EQUAL_HEX8(data, sector_buf[i]);
     }
 }
 
@@ -412,17 +413,22 @@ FLASH_TEST_CASE_3("SPI flash unaligned read/write", test_unaligned_read_write);
 
 void test_single_read_write(esp_flash_t* chip)
 {
+    const int seed = 699;
     ESP_LOGI(TAG, "Testing chip %p...", chip);
     uint32_t offs = erase_test_region(chip, 2);
 
+    srand(seed);
     for (unsigned v = 0; v < 512; v++) {
-        TEST_ASSERT_EQUAL_HEX(ESP_OK, esp_flash_write(chip, &v, offs + v, 1) );
+        uint32_t data = rand();
+        TEST_ASSERT_EQUAL_HEX(ESP_OK, esp_flash_write(chip, &data, offs + v, 1) );
     }
 
+    srand(seed);
     for (unsigned v = 0; v < 512; v++) {
         uint8_t readback;
+        uint32_t data = rand();
         TEST_ASSERT_EQUAL_HEX(ESP_OK, esp_flash_read(chip, &readback, offs + v, 1) );
-        TEST_ASSERT_EQUAL_HEX8(v, readback);
+        TEST_ASSERT_EQUAL_HEX8(data, readback);
     }
 }
 
@@ -435,18 +441,23 @@ FLASH_TEST_CASE_3("SPI flash single byte reads/writes", test_single_read_write);
 */
 void test_three_byte_read_write(esp_flash_t *chip)
 {
+    const int seed = 700;
     ESP_LOGI(TAG, "Testing chip %p...", chip);
     uint32_t offs = erase_test_region(chip, 2);
     ets_printf("offs:%X\n", offs);
 
-    for (uint32_t v = 0; v < 2000; v++) {
-        TEST_ASSERT_EQUAL(ESP_OK, esp_flash_write(chip, &v, offs + 3 * v, 3) );
+    srand(seed);
+    for (uint32_t v = 0; v < 86; v++) {
+        uint32_t data = rand();
+        TEST_ASSERT_EQUAL(ESP_OK, esp_flash_write(chip, &data, offs + 3 * v, 3) );
     }
 
-    for (uint32_t v = 0; v < 2000; v++) {
+    srand(seed);
+    for (uint32_t v = 0; v < 1; v++) {
         uint32_t readback;
+        uint32_t data = rand();
         TEST_ASSERT_EQUAL(ESP_OK, esp_flash_read(chip, &readback, offs + 3 * v, 3) );
-        TEST_ASSERT_EQUAL_HEX32(v & 0xFFFFFF, readback & 0xFFFFFF);
+        TEST_ASSERT_EQUAL_HEX32(data & 0xFFFFFF, readback & 0xFFFFFF);
     }
 }