diff --git a/src/tree_schema_free.c b/src/tree_schema_free.c
index c6c9344..561226c 100644
--- a/src/tree_schema_free.c
+++ b/src/tree_schema_free.c
@@ -616,7 +616,7 @@
 {
     LY_ARRAY_COUNT_TYPE u, v, w;
     const struct lysp_submodule *submod;
-    const struct lysp_module *base_pmod;
+    const struct lysp_module *base_pmod = NULL;
     const struct lysp_ident *identp = NULL;
     const struct lys_module *mod;
     const char *base_name;