diff --git a/NEWS.md b/NEWS.md
index 690e2e4..6775872 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -43,6 +43,13 @@
   `create_mock_data()` stops and names the formula variables. Previously the
   legacy generator ignored the formula and returned unrelated random values,
   or dropped a `DerivedVar::` variable, without saying so.
+- On the legacy path (`validate = FALSE` and the other legacy triggers),
+  `create_mock_data()` now generates only variables whose variable-level
+  `databaseStart` includes the requested database, as the v0.4 pipeline
+  does. Previously it chose variables from the detail rows alone, so a
+  variable listed only for another database was generated as random values,
+  and a formula or survival variable belonging to another database stopped
+  the run.
 
 ## New features
 
diff --git a/R/create_mock_data.R b/R/create_mock_data.R
index 0dd6284..eeb1cfd 100644
--- a/R/create_mock_data.R
+++ b/R/create_mock_data.R
@@ -395,6 +395,15 @@ create_mock_data <- function(databaseStart,
     enabled_vars <- variables
   }
 
+  # Variable-level databaseStart lists the databases a variable belongs to.
+  # The v0.4 adapter honours it; the legacy path used only detail rows, so a
+  # variable listed only for another database was generated here as random
+  # values, and the formula and survival guards below stopped on it. Same
+  # matcher and empty-means-all rule as the adapter.
+  if ("databaseStart" %in% names(enabled_vars)) {
+    enabled_vars <- .filter_recodeflow_by_database(enabled_vars, databaseStart, allow_empty = TRUE)
+  }
+
   # Formula variables are computed only by the v0.4 pipeline; the legacy
   # dispatcher ignores mockFormula and would return unrelated random values,
   # or drop a DerivedVar:: variable, without saying so. Checked before the
diff --git a/tests/testthat/test-create-mock-data-v04.R b/tests/testthat/test-create-mock-data-v04.R
index 8a09c5f..e69dca8 100644
--- a/tests/testthat/test-create-mock-data-v04.R
+++ b/tests/testthat/test-create-mock-data-v04.R
@@ -277,3 +277,66 @@ test_that("create_mock_data v0.4 and legacy paths are distributionally aligned",
   expect_type(attr(v04, "mockdata_diagnostics"), "list")
   expect_null(attr(legacy, "mockdata_diagnostics"))
 })
+
+test_that("the legacy path generates only variables that belong to the requested database", {
+  # Release review of 0.5.0: the legacy path chose variables by detail rows
+  # and ignored variable-level databaseStart, which the v0.4 adapter honours.
+  # A variable listed only for "other" was generated for "study" (as random
+  # values), and the formula and survival guards stopped "study" on variables
+  # that do not belong to it.
+  run <- function(v, d) {
+    suppressWarnings(suppressMessages(
+      create_mock_data("study", v, d, n = 20, seed = 1, validate = FALSE)
+    ))
+  }
+  details_for <- function(variables, other_only) {
+    data.frame(
+      variable = variables$variable,
+      recStart = c("[0,1]", "[0,1]"),
+      recEnd = "copy",
+      proportion = 1,
+      databaseStart = c("study, other", other_only),
+      stringsAsFactors = FALSE
+    )
+  }
+  plain <- data.frame(
+    variable = c("x", "z"),
+    variableType = "Continuous",
+    rType = "double",
+    role = "enabled",
+    databaseStart = c("study, other", "other"),
+    distribution = "uniform",
+    stringsAsFactors = FALSE
+  )
+  # Shared detail rows and "other"-only detail rows behave the same.
+  for (z_rows in c("study, other", "other")) {
+    expect_identical(names(run(plain, details_for(plain, z_rows))), "x", info = z_rows)
+
+    formula_details <- details_for(plain, z_rows)
+    formula_details$mockFormula <- c("", "x * 2")
+    expect_identical(names(run(plain, formula_details)), "x", info = z_rows)
+  }
+
+  survival <- data.frame(
+    variable = c("entry", "death"),
+    variableType = "Date",
+    rType = "date",
+    role = "enabled",
+    databaseStart = c("study, other", "other"),
+    distribution = "uniform",
+    anchor = c("", "entry"),
+    followup_min = c(NA, 0),
+    followup_max = c(NA, 10),
+    event_prop = c(NA, 1),
+    stringsAsFactors = FALSE
+  )
+  survival_details <- data.frame(
+    variable = "entry",
+    recStart = "[2001-01-01,2001-12-31]",
+    recEnd = "copy",
+    proportion = 1,
+    databaseStart = "study, other",
+    stringsAsFactors = FALSE
+  )
+  expect_identical(names(run(survival, survival_details)), "entry")
+})