diff --git a/src/platform/nm-linux-platform.c b/src/platform/nm-linux-platform.c
index edc8fe4143..defe7c92c8 100644
--- a/src/platform/nm-linux-platform.c
+++ b/src/platform/nm-linux-platform.c
@@ -1602,7 +1602,7 @@ sysctl_set (NMPlatform *platform, const char *path, const char *value)
 	g_assert (g_str_has_prefix (path, "/proc/sys/")
 	          || g_str_has_prefix (path, "/sys/"));
 	/* Don't write to suspicious locations */
-	g_assert (!strstr (path, "/.."));
+	g_assert (!strstr (path, "/../"));
 
 	fd = open (path, O_WRONLY | O_TRUNC);
 	if (fd == -1) {
@@ -1701,7 +1701,7 @@ sysctl_get (NMPlatform *platform, const char *path)
 	g_assert (g_str_has_prefix (path, "/proc/sys/")
 	          || g_str_has_prefix (path, "/sys/"));
 	/* Don't write to suspicious locations */
-	g_assert (!strstr (path, "/.."));
+	g_assert (!strstr (path, "/../"));
 
 	if (!g_file_get_contents (path, &contents, NULL, &error)) {
 		/* We assume FAILED means EOPNOTSUP */