diff --git a/drivers/include/mrf24j40.h b/drivers/include/mrf24j40.h
index d94d071aba..cfc89c4a30 100644
--- a/drivers/include/mrf24j40.h
+++ b/drivers/include/mrf24j40.h
@@ -224,11 +224,10 @@ void mrf24j40_set_addr_short(mrf24j40_t *dev, uint16_t addr);
 /**
  * @brief   Get the configured long address of the given device
  *
- * @param[in] dev           device to read from
- *
- * @return                  the currently set (8-byte) long address
+ * @param[in]  dev          device to read from
+ * @param[out] addr         the currently set (8-byte) long address
  */
-uint64_t mrf24j40_get_addr_long(mrf24j40_t *dev);
+void mrf24j40_get_addr_long(mrf24j40_t *dev, uint8_t *addr);
 
 /**
  * @brief   Set the long address of the given device
@@ -236,7 +235,7 @@ uint64_t mrf24j40_get_addr_long(mrf24j40_t *dev);
  * @param[in] dev           device to write to
  * @param[in] addr          (8-byte) long address to set
  */
-void mrf24j40_set_addr_long(mrf24j40_t *dev, uint64_t addr);
+void mrf24j40_set_addr_long(mrf24j40_t *dev, const uint8_t *addr);
 
 /**
  * @brief   Get the configured channel number of the given device
diff --git a/drivers/mrf24j40/mrf24j40.c b/drivers/mrf24j40/mrf24j40.c
index 13982fb239..a4be2ec044 100644
--- a/drivers/mrf24j40/mrf24j40.c
+++ b/drivers/mrf24j40/mrf24j40.c
@@ -55,7 +55,7 @@ int mrf24j40_reset(mrf24j40_t *dev)
     netdev_ieee802154_setup(&dev->netdev);
 
     /* set short and long address */
-    mrf24j40_set_addr_long(dev, unaligned_get_u64(dev->netdev.long_addr));
+    mrf24j40_set_addr_long(dev, dev->netdev.long_addr);
     mrf24j40_set_addr_short(dev, unaligned_get_u16(dev->netdev.short_addr));
 
     mrf24j40_set_chan(dev, CONFIG_IEEE802154_DEFAULT_CHANNEL);
diff --git a/drivers/mrf24j40/mrf24j40_getset.c b/drivers/mrf24j40/mrf24j40_getset.c
index 304bc3644d..3249fbd891 100644
--- a/drivers/mrf24j40/mrf24j40_getset.c
+++ b/drivers/mrf24j40/mrf24j40_getset.c
@@ -157,24 +157,17 @@ void mrf24j40_set_addr_short(mrf24j40_t *dev, uint16_t addr)
                              naddr.u8[0]);
 }
 
-uint64_t mrf24j40_get_addr_long(mrf24j40_t *dev)
+void mrf24j40_get_addr_long(mrf24j40_t *dev, uint8_t *addr)
 {
-    network_uint64_t naddr;
-
     for (int i = 0; i < 8; i++) {
-        naddr.u8[7 - i] = mrf24j40_reg_read_short(dev, (MRF24J40_REG_EADR0 + i));
+        addr[7 - i] = mrf24j40_reg_read_short(dev, MRF24J40_REG_EADR0 + i);
     }
-    return naddr.u64;
 }
 
-void mrf24j40_set_addr_long(mrf24j40_t *dev, uint64_t addr)
+void mrf24j40_set_addr_long(mrf24j40_t *dev, const uint8_t *addr)
 {
-    network_uint64_t naddr;
-    naddr.u64 = addr;
-
     for (int i = 0; i < 8; i++) {
-        mrf24j40_reg_write_short(dev, (MRF24J40_REG_EADR0 + i),
-                                 (naddr.u8[7 - i]));
+        mrf24j40_reg_write_short(dev, MRF24J40_REG_EADR0 + i, addr[7 - i]);
     }
 }
 
diff --git a/drivers/mrf24j40/mrf24j40_netdev.c b/drivers/mrf24j40/mrf24j40_netdev.c
index 5604f2854f..253291e820 100644
--- a/drivers/mrf24j40/mrf24j40_netdev.c
+++ b/drivers/mrf24j40/mrf24j40_netdev.c
@@ -184,7 +184,7 @@ static int _get(netdev_t *netdev, netopt_t opt, void *val, size_t max_len)
                 res = -EOVERFLOW;
             }
             else {
-                *(uint64_t*)val = mrf24j40_get_addr_long(dev);
+                mrf24j40_get_addr_long(dev, val);
                 res = sizeof(uint64_t);
             }
             break;
@@ -400,7 +400,7 @@ static int _set(netdev_t *netdev, netopt_t opt, const void *val, size_t len)
                 res = -EOVERFLOW;
             }
             else {
-                mrf24j40_set_addr_long(dev, *((const uint64_t *)val));
+                mrf24j40_set_addr_long(dev, val);
                 res = sizeof(uint64_t);
             }
             break;