diff --git a/libbb/platform.c b/libbb/platform.c
index 03bbb798b..d2b263a6d 100644
--- a/libbb/platform.c
+++ b/libbb/platform.c
@@ -107,7 +107,8 @@ void* FAST_FUNC memrchr(const void *s, int c, size_t n)
 /* This is now actually part of POSIX.1, but was only added in 2008 */
 char* FAST_FUNC mkdtemp(char *template)
 {
-	if (mktemp(template) == NULL || mkdir(template, 0700) != 0)
+	/* NB: on error, mktemp returns an empty string, not NULL */
+	if (mktemp(template)[0] == '\0' || mkdir(template, 0700) != 0)
 		return NULL;
 	return template;
 }