diff --git a/libnfc/buses/spi_posix.c b/libnfc/buses/spi_posix.c
index fdf000a..e862bdf 100644
--- a/libnfc/buses/spi_posix.c
+++ b/libnfc/buses/spi_posix.c
@@ -271,7 +271,10 @@ spi_list_ports(void)
 
   DIR *pdDir = opendir("/dev");
   struct dirent *pdDirEnt;
-  while ((pdDirEnt = readdir(pdDir)) != NULL) {
+  struct dirent entry;
+  struct dirent *result;
+  while ((readdir_r(pdDir, &entry, &result) == 0) && (result != NULL)) {
+    pdDirEnt = &entry;
 #if !defined(__APPLE__)
     if (!isdigit(pdDirEnt->d_name[strlen(pdDirEnt->d_name) - 1]))
       continue;