diff --git a/sam_api.c b/sam_api.c
index 615d260..098ca63 100644
--- a/sam_api.c
+++ b/sam_api.c
@@ -59,7 +59,11 @@ uint8_t select_desfire_app_no_le[] =
 uint8_t FILE_NOT_FOUND[] = {0x6a, 0x82};
 
 void* calloc(size_t count, size_t size) {
-    return malloc(count * size);
+    void* ptr = malloc(count * size);
+    if(ptr) {
+        memset(ptr, 0, count * size);
+    }
+    return ptr;
 }
 
 // Forward declarations
diff --git a/seader_worker.c b/seader_worker.c
index c13928e..2cd256f 100644
--- a/seader_worker.c
+++ b/seader_worker.c
@@ -19,7 +19,7 @@ void seader_send_card_detected(SeaderUartBridge* seader_uart, CardDetails_t* car
 /***************************** Seader Worker API *******************************/
 
 SeaderWorker* seader_worker_alloc() {
-    SeaderWorker* seader_worker = malloc(sizeof(SeaderWorker));
+    SeaderWorker* seader_worker = calloc(1, sizeof(SeaderWorker));
 
     // Worker thread attributes
     seader_worker->thread =