diff --git a/spec/session/serialisation.spec.ts b/spec/session/serialisation.spec.ts
index 591d6401273cb891be9c27f94ed319dcfd917a55..6a6e93e90b724cf62df6f097c9bf54b12fb2a75a 100644
--- a/spec/session/serialisation.spec.ts
+++ b/spec/session/serialisation.spec.ts
@@ -144,7 +144,7 @@ describe("serialising / deserialising session - ", () => {
         );
         const section = new cSnCirc(paramSection);
         const sp = new SectionParametree(section);
-        sp.section.prms.Ks.v = 42;
+        sp.section.prms.Ks.singleValue = 42;
 
         const serialised = sp.serialise();
         expect(serialised).toContain('{"symbol":"Ks","mode":"SINGLE","value":42}');