diff --git a/client/src/cmdhfmfhard.c b/client/src/cmdhfmfhard.c
index 713a658e9..f8f894e3c 100644
--- a/client/src/cmdhfmfhard.c
+++ b/client/src/cmdhfmfhard.c
@@ -1930,7 +1930,7 @@ static void add_matching_states(statelist_t *cands, uint8_t part_sum_a0, uint8_t
 
     const uint32_t worstcase_size = 1 << 20;
 
-    cands->states[odd_even] = (uint32_t *)malloc(sizeof(uint32_t) * worstcase_size);
+    cands->states[odd_even] = (uint32_t *)calloc(sizeof(uint32_t) * worstcase_size, sizeof(uint8_t));
     if (cands->states[odd_even] == NULL) {
         PrintAndLogEx(ERR, "Out of memory error in add_matching_states() - statelist.\n");
         exit(4);
diff --git a/client/src/cmdhfntag424.c b/client/src/cmdhfntag424.c
index 277b2ec18..e1593500b 100644
--- a/client/src/cmdhfntag424.c
+++ b/client/src/cmdhfntag424.c
@@ -288,7 +288,7 @@ static void ntag424_calc_mac(ntag424_session_keys_t *session_keys, uint8_t comma
 
     int mac_input_len = sizeof(mac_input_header) + datalen;
 
-    uint8_t *mac_input = (uint8_t *)malloc(mac_input_len);
+    uint8_t *mac_input = (uint8_t *)calloc(mac_input_len, sizeof(uint8_t));
     memcpy(mac_input, mac_input_header, sizeof(mac_input_header));
     memcpy(&mac_input[sizeof(mac_input_header)], data, datalen);
     uint8_t mac[16] = {0};
diff --git a/client/src/loclass/elite_crack.c b/client/src/loclass/elite_crack.c
index 5d2be50e6..c5fd2c534 100644
--- a/client/src/loclass/elite_crack.c
+++ b/client/src/loclass/elite_crack.c
@@ -365,7 +365,7 @@ static void *bf_thread(void *thread_arg) {
         // success
         if (memcmp(calculated_MAC, mac, 4) == 0) {
 
-            loclass_thread_ret_t *r = (loclass_thread_ret_t *)malloc(sizeof(loclass_thread_ret_t));
+            loclass_thread_ret_t *r = (loclass_thread_ret_t *)calloc(sizeof(loclass_thread_ret_t), sizeof(uint8_t));
 
             for (uint8_t i = 0 ; i < numbytes_to_recover; i++) {
                 r->values[i] = keytable[bytes_to_recover[i]] & 0xFF;
diff --git a/client/src/uart/ringbuffer.c b/client/src/uart/ringbuffer.c
index 345abdf5a..b0ed173e3 100644
--- a/client/src/uart/ringbuffer.c
+++ b/client/src/uart/ringbuffer.c
@@ -2,7 +2,7 @@
 #include <stdlib.h>
 
 RingBuffer *RingBuf_create(int capacity) {
-    RingBuffer *buffer = (RingBuffer *)malloc(sizeof(RingBuffer));
+    RingBuffer *buffer = (RingBuffer *)calloc(sizeof(RingBuffer), sizeof(uint8_t));
     if (!buffer) {
         return NULL;
     }
diff --git a/tools/hitag2crack/crack2/ht2crack2buildtable.c b/tools/hitag2crack/crack2/ht2crack2buildtable.c
index 15f1cb192..29d8987d0 100644
--- a/tools/hitag2crack/crack2/ht2crack2buildtable.c
+++ b/tools/hitag2crack/crack2/ht2crack2buildtable.c
@@ -452,7 +452,7 @@ int main(int argc, char *argv[]) {
     void *status;
 
     // make the table of tables
-    t = (struct table *)malloc(sizeof(struct table) * 65536);
+    t = (struct table *)calloc(sizeof(struct table) * 65536, sizeof(uint8_t));
     if (!t) {
         printf("malloc failed\n");
         exit(1);
diff --git a/tools/hitag2crack/crack3/ht2crack3.c b/tools/hitag2crack/crack3/ht2crack3.c
index f50ea6af4..3a185f9a4 100644
--- a/tools/hitag2crack/crack3/ht2crack3.c
+++ b/tools/hitag2crack/crack3/ht2crack3.c
@@ -196,7 +196,7 @@ static void *crack(void *d) {
     numnrar = data->numnrar;
 
     // create space for tables
-    Tk = (struct Tklower *)malloc(sizeof(struct Tklower) * 0x40000);
+    Tk = (struct Tklower *)calloc(sizeof(struct Tklower) * 0x40000, sizeof(uint8_t));
     if (!Tk) {
         printf("Failed to allocate memory (Tk)\n");
         exit(1);
@@ -314,7 +314,7 @@ int main(int argc, char *argv[]) {
     }
 
     // create table of nR aR pairs
-    TnRaR = (struct nRaR *)malloc(sizeof(struct nRaR) * NUM_NRAR);
+    TnRaR = (struct nRaR *)calloc(sizeof(struct nRaR) * NUM_NRAR, sizeof(uint8_t));
 
     // open file
     fp = fopen(argv[2], "r");