diff --git a/CHANGELOG.md b/CHANGELOG.md
index ba2f8f322..1d8a9226b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+ - Fixed broken `lf em 4x70 brute` command (@adite)
  - Fixed the lf sampling when bits_per_sample is less than 8 (@wh201906)
  - Added `lf em 4x70 brute` command (@adite)
 
diff --git a/armsrc/em4x70.c b/armsrc/em4x70.c
index 545491447..066aad58f 100644
--- a/armsrc/em4x70.c
+++ b/armsrc/em4x70.c
@@ -362,7 +362,7 @@ static int bruteforce(const uint8_t address, const uint8_t *rnd, const uint8_t *
     uint8_t rev_rnd[7];
     uint8_t temp_rnd[7];
 
-    reverse_arraycopy((uint8_t *)rnd, rev_rnd, sizeof(rnd));
+    reverse_arraycopy((uint8_t *)rnd, rev_rnd, sizeof(rev_rnd));
     memcpy(temp_rnd, rnd, sizeof(temp_rnd));
 
     for (int k = start_key; k <= 0xFFFF; ++k) {
diff --git a/client/src/cmdlfem4x70.c b/client/src/cmdlfem4x70.c
index f008d9947..e90c688c1 100644
--- a/client/src/cmdlfem4x70.c
+++ b/client/src/cmdlfem4x70.c
@@ -306,8 +306,8 @@ int CmdEM4x70Brute(const char *Cmd) {
             break;
         }
 
-        // should be done in about 30 minutes
-        if (timeout > ((30 * 60000) / TIMEOUT)) {
+        // should be done in about 60 minutes.
+        if (timeout > ((60 * 60000) / TIMEOUT)) {
             PrintAndLogEx(WARNING, "\nNo response from Proxmark3. Aborting...");
             break;
         }