diff --git a/src/spicelib/devices/bsimsoi/b4soidest.c b/src/spicelib/devices/bsimsoi/b4soidest.c
index c66c177ce..0705e6df0 100644
--- a/src/spicelib/devices/bsimsoi/b4soidest.c
+++ b/src/spicelib/devices/bsimsoi/b4soidest.c
@@ -24,6 +24,11 @@ B4SOIdestroy(GENmodel **inModel)
 {
     B4SOImodel *mod = *(B4SOImodel**) inModel;
 
+#ifdef USE_OMP
+    /* free just once for all models */
+    FREE(mod->B4SOIInstanceArray);
+#endif
+
     while (mod) {
         B4SOImodel *next_mod = mod->B4SOInextModel;
         B4SOIinstance *inst = mod->B4SOIinstances;