diff --git a/core/vmmapi.c b/core/vmmapi.c
index ffc3dc750..16efd8716 100644
--- a/core/vmmapi.c
+++ b/core/vmmapi.c
@@ -118,7 +118,7 @@ vm_open(const char *name)
 	int error, retry = 10;
 	uuid_t vm_uuid;
 
-	ctx = malloc(sizeof(struct vmctx) + strlen(name) + 1);
+	ctx = calloc(1, sizeof(struct vmctx) + strlen(name) + 1);
 	assert(ctx != NULL);
 	assert(devfd == -1);
 
diff --git a/hw/platform/rtc.c b/hw/platform/rtc.c
index 52650ea80..a58839151 100644
--- a/hw/platform/rtc.c
+++ b/hw/platform/rtc.c
@@ -1105,9 +1105,8 @@ vrtc_init(struct vmctx *ctx, int local_time)
 	time_t curtime;
 	struct inout_port rtc_addr, rtc_data;
 
-	vrtc = malloc(sizeof(struct vrtc));
+	vrtc = calloc(1, sizeof(struct vrtc));
 	assert(vrtc != NULL);
-	memset(vrtc, 0, sizeof(struct vrtc));
 	vrtc->vm = ctx;
 	ctx->vrtc = vrtc;
 
diff --git a/tools/acrntrace/acrntrace.c b/tools/acrntrace/acrntrace.c
index 2c9f7e4f3..5817e7596 100644
--- a/tools/acrntrace/acrntrace.c
+++ b/tools/acrntrace/acrntrace.c
@@ -340,12 +340,11 @@ int main(int argc, char *argv[])
 
 	/* how many cpus */
 	pcpu_num = get_cpu_num();
-	reader = malloc(sizeof(reader_struct) * pcpu_num);
+	reader = calloc(1, sizeof(reader_struct) * pcpu_num);
 	if (!reader) {
 		pr_err("Failed to allocate reader memory\n");
 		exit(EXIT_FAILURE);
 	}
-	memset(reader, 0, sizeof(reader_struct) * pcpu_num);
 
 	/* create dir for trace file */
 	if (create_trace_file_dir(trace_file_dir)) {