diff --git a/src/test/app/TestHostFunctions.h b/src/test/app/TestHostFunctions.h
index 11d613bc8d..040db53f10 100644
--- a/src/test/app/TestHostFunctions.h
+++ b/src/test/app/TestHostFunctions.h
@@ -292,7 +292,7 @@ public:
     Expected<int32_t, HostFunctionError>
     updateData(Slice const& data) override
     {
-        return 0;
+        return data.size();
     }
 
     Expected<int32_t, HostFunctionError>
diff --git a/src/test/app/wasm_fixtures/codecov_tests/src/lib.rs b/src/test/app/wasm_fixtures/codecov_tests/src/lib.rs
index f02550ba96..8d72443fb7 100644
--- a/src/test/app/wasm_fixtures/codecov_tests/src/lib.rs
+++ b/src/test/app/wasm_fixtures/codecov_tests/src/lib.rs
@@ -162,7 +162,7 @@ pub extern "C" fn finish() -> i32 {
     );
     check_result(
         unsafe { host::update_data(account.0.as_ptr(), account.0.len()) },
-        0,
+        20,
         "update_data",
     );
     with_buffer::<32, _, _>(|ptr, len| {
diff --git a/src/test/app/wasm_fixtures/fixtures.cpp b/src/test/app/wasm_fixtures/fixtures.cpp
index 5f845fbe78..624243a3ee 100644
--- a/src/test/app/wasm_fixtures/fixtures.cpp
+++ b/src/test/app/wasm_fixtures/fixtures.cpp
@@ -9947,7 +9947,7 @@ extern std::string const codecovTestsWasmHex =
     "103c4189803c1010412041a881c0004120103c41014189803c1011412041c881c000411810"
     "3c20012000280298011012412041e081c0004117103c20012000280298011013412041f781"
     "c0004127103c4101200120002802980110144120419e82c000411f103c200041246a220441"
-    "141015410041bd82c000410b103c200041e0016a2206420037030020024200370300200342"
+    "141015411441bd82c000410b103c200041e0016a2206420037030020024200370300200342"
     "00370300200042003703c8012001200028029801200541201016412041bc8dc0004113103c"
     "41c882c000410c41d482c000410b41df82c000410e1017410141ed82c0004109103c200041"
     "b8016a200041186a290300370300200041b0016a200041106a290300370300200041a8016a"