diff --git a/src/frontend/numparam/spicenum.c b/src/frontend/numparam/spicenum.c
index 7943c1273..f9c3b9ffc 100644
--- a/src/frontend/numparam/spicenum.c
+++ b/src/frontend/numparam/spicenum.c
@@ -191,10 +191,13 @@ findsubname(dico_t *dico, SPICE_DSTRINGPTR dstr_p)
             entry = entrynb(dico, spice_dstring_value(&name));
             if (entry && (entry->tp == NUPA_SUBCKT)) {
                 spice_dstring_setlength(dstr_p, (int) (p_end - s));
+                spice_dstring_free(&name);
                 return;
             }
         }
     }
+
+    spice_dstring_free(&name);
 }
 
 
diff --git a/src/frontend/numparam/xpressn.c b/src/frontend/numparam/xpressn.c
index 39b61e8a6..655ce9a34 100644
--- a/src/frontend/numparam/xpressn.c
+++ b/src/frontend/numparam/xpressn.c
@@ -556,6 +556,7 @@ findsubckt(dico_t *dico, const char * const s)
 
     pscopy(&ustr, name_b, name_e);
     entry = entrynb(dico, spice_dstring_value(&ustr));
+    spice_dstring_free(&ustr);
 
     if (entry && (entry->tp == NUPA_SUBCKT)) {
         return entry->ivl;