diff --git a/client/tinycbor/open_memstream.c b/client/tinycbor/open_memstream.c
index 18f3de8b1..f618db8ae 100644
--- a/client/tinycbor/open_memstream.c
+++ b/client/tinycbor/open_memstream.c
@@ -90,7 +90,7 @@ static int close_buffer(void *cookie)
 
 FILE *open_memstream(char **bufptr, size_t *lenptr)
 {
-    struct Buffer *b = (struct Buffer *)malloc(sizeof(struct Buffer));
+    struct Buffer *b = (struct Buffer *)calloc(sizeof(struct Buffer), sizeof(uint8_t));
     if (b == NULL)
         return NULL;
     b->alloc = 0;
diff --git a/client/ui.c b/client/ui.c
index a0151a8db..71603fed6 100644
--- a/client/ui.c
+++ b/client/ui.c
@@ -196,7 +196,7 @@ void SetFlushAfterWrite(bool value) {
 
 	int i,j;
 	
-	int * output =  (int* ) malloc(sizeof(int) * len);	
+	int * output =  (int* ) calloc(sizeof(int) * len, sizeof(uint8_t));	
 	if ( !output ) return;
 	
 	// clear mem
diff --git a/client/util.c b/client/util.c
index b22258d44..c4d6ae5a4 100644
--- a/client/util.c
+++ b/client/util.c
@@ -884,8 +884,8 @@ extern void strcreplace(char *buf, size_t len, char from, char to) {
 }
 
 extern char *strmcopy(char *buf) {
-	char* str = NULL;
-	if ((str = (char*) malloc(strlen(buf) + 1)) != NULL) {
+	char* str = (char*) calloc(strlen(buf) + 1, sizeof(uint8_t));
+	if (str != NULL) {
 		memset(str, 0, strlen(buf) + 1);
 		strcpy(str, buf);
 	}	
diff --git a/common/crapto1/crapto1.c b/common/crapto1/crapto1.c
index 8dc8f26c8..af1ed8167 100644
--- a/common/crapto1/crapto1.c
+++ b/common/crapto1/crapto1.c
@@ -405,7 +405,7 @@ int nonce_distance(uint32_t from, uint32_t to)
 {
 	uint16_t x, i;
 	if(!dist) {
-		dist = malloc(2 << 16);
+		dist = calloc(2 << 16,  sizeof(uint8_t));
 		if(!dist)
 			return -1;
 		for (x = i = 1; i; ++i) {
@@ -443,7 +443,7 @@ static uint32_t fastfwd[2][8] = {
  */
 uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)
 {
-	uint32_t *candidates = malloc(4 << 10);
+	uint32_t *candidates = calloc(4 << 10, sizeof(uint8_t));
 	if (!candidates) return 0;
 	
 	uint32_t c,  entry;
diff --git a/common/radixsort.c b/common/radixsort.c
index 91495316c..981c19191 100644
--- a/common/radixsort.c
+++ b/common/radixsort.c
@@ -3,7 +3,7 @@
 uint64_t * radixSort(uint64_t * array, uint32_t size) {
     rscounts_t counts;
     memset(&counts, 0, 256 * 8 * sizeof(uint32_t));
-    uint64_t * cpy = (uint64_t *)malloc(size * sizeof(uint64_t));
+    uint64_t * cpy = (uint64_t *)calloc(size * sizeof(uint64_t), sizeof(uint8_t));
     uint32_t o8=0, o7=0, o6=0, o5=0, o4=0, o3=0, o2=0, o1=0;
     uint32_t t8, t7, t6, t5, t4, t3, t2, t1;
     uint32_t x;
diff --git a/uart/uart_posix.c b/uart/uart_posix.c
index d857729d6..cb878a4f0 100644
--- a/uart/uart_posix.c
+++ b/uart/uart_posix.c
@@ -75,7 +75,7 @@ const struct timeval timeout = {
 
 serial_port uart_open(const char* pcPortName)
 {
-  serial_port_unix* sp = malloc(sizeof(serial_port_unix));
+  serial_port_unix* sp = calloc(sizeof(serial_port_unix), sizeof(uint8_t));
   if (sp == 0) return INVALID_SERIAL_PORT;
 
   if (memcmp(pcPortName, "tcp:", 4) == 0) {
diff --git a/uart/uart_win32.c b/uart/uart_win32.c
index 11c90f15f..438f586c8 100644
--- a/uart/uart_win32.c
+++ b/uart/uart_win32.c
@@ -50,7 +50,7 @@ typedef struct {
 
 serial_port uart_open(const char* pcPortName) {
 	char acPortName[255];
-	serial_port_windows* sp = malloc(sizeof(serial_port_windows));
+	serial_port_windows* sp = calloc(sizeof(serial_port_windows), sizeof(uint8_t));
 
 	if (sp == 0) {
 		printf("[!] UART failed to allocate memory\n");