diff --git a/libfprint/drivers/elanmoc/elanmoc.c b/libfprint/drivers/elanmoc/elanmoc.c
index 0261bfff..e86b79a2 100644
--- a/libfprint/drivers/elanmoc/elanmoc.c
+++ b/libfprint/drivers/elanmoc/elanmoc.c
@@ -50,9 +50,9 @@ elanmoc_compose_cmd (
   const struct elanmoc_cmd *cmd_info
                     )
 {
-  g_autofree char *cmd_buf = NULL;
+  g_autofree uint8_t *cmd_buf = NULL;
 
-  cmd_buf = g_malloc0 (cmd_info->cmd_len);
+  cmd_buf = g_new0 (uint8_t, cmd_info->cmd_len);
   if(cmd_info->cmd_len < ELAN_MAX_HDR_LEN)
     memcpy (cmd_buf, &cmd_info->cmd_header, cmd_info->cmd_len);
   else
diff --git a/libfprint/drivers/focaltech_moc/focaltech_moc.c b/libfprint/drivers/focaltech_moc/focaltech_moc.c
index 190ab436..9872c7c7 100644
--- a/libfprint/drivers/focaltech_moc/focaltech_moc.c
+++ b/libfprint/drivers/focaltech_moc/focaltech_moc.c
@@ -126,12 +126,12 @@ fp_cmd_bcc (uint8_t *data, uint16_t len)
 static uint8_t *
 focaltech_moc_compose_cmd (uint8_t cmd, const uint8_t *data, uint16_t len)
 {
-  g_autofree char *cmd_buf = NULL;
+  g_autofree uint8_t *cmd_buf = NULL;
   FpCmd *fp_cmd = NULL;
   uint8_t *bcc = NULL;
   uint16_t header_len = len + sizeof (*bcc);
 
-  cmd_buf = g_malloc0 (sizeof (FpCmd) + header_len);
+  cmd_buf = g_new0 (uint8_t, sizeof (FpCmd) + header_len);
 
   fp_cmd = (FpCmd *) cmd_buf;
 
diff --git a/libfprint/fp-device-private.h b/libfprint/fp-device-private.h
index 759a678f..1c3702fa 100644
--- a/libfprint/fp-device-private.h
+++ b/libfprint/fp-device-private.h
@@ -44,7 +44,7 @@ typedef struct
   FpDeviceType type;
 
   GUsbDevice  *usb_device;
-  const gchar *virtual_env;
+  gchar       *virtual_env;
   struct
   {
     gchar *spidev_path;
diff --git a/libfprint/fpi-ssm.c b/libfprint/fpi-ssm.c
index c34498ab..b816945f 100644
--- a/libfprint/fpi-ssm.c
+++ b/libfprint/fpi-ssm.c
@@ -73,7 +73,7 @@
 struct _FpiSsm
 {
   FpDevice               *dev;
-  const char             *name;
+  char                   *name;
   FpiSsm                 *parentsm;
   gpointer                ssm_data;
   GDestroyNotify          ssm_data_destroy;