diff --git a/src/parser.c b/src/parser.c
index db65bb808..e7089b550 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -299,6 +299,11 @@ lyp_mmap(struct ly_ctx *ctx, int fd, size_t addsize, size_t *length, void **addr
 int
 lyp_munmap(void *addr, size_t length)
 {
+    if (!addr) {
+        /* nothing to unmap */
+        return 0;
+    }
+
     return munmap(addr, length);
 }
 
diff --git a/src/tree_data.c b/src/tree_data.c
index c3a2ece0b..566bf33cf 100644
--- a/src/tree_data.c
+++ b/src/tree_data.c
@@ -935,7 +935,7 @@ lyd_parse_(struct ly_ctx *ctx, const struct lyd_node *rpc_act, const char *data,
     struct lyd_node *result = NULL;
     int xmlopt = LYXML_PARSE_MULTIROOT;
 
-    if (!ctx || !data) {
+    if (!ctx) {
         LOGARG;
         return NULL;
     }
@@ -1069,8 +1069,6 @@ lyd_parse_fd_(struct ly_ctx *ctx, int fd, LYD_FORMAT format, int options, va_lis
     if (lyp_mmap(ctx, fd, 0, &length, (void **)&data)) {
         LOGERR(ctx, LY_ESYS, "Mapping file descriptor into memory failed (%s()).", __func__);
         return NULL;
-    } else if (!data) {
-        return NULL;
     }
 
     ret = lyd_parse_data_(ctx, data, format, options, ap);