diff --git a/R/mvgam.R b/R/mvgam.R
index bd73bc07..076d0c06 100644
--- a/R/mvgam.R
+++ b/R/mvgam.R
@@ -683,6 +683,12 @@ mvgam = function(formula,
                                       drift = drift,
                                       noncentred = noncentred)
 
+  # Cannot yet map observations to trends that evolve as CAR1
+  if(trend_model == 'CAR1' & !missing(trend_map)){
+    stop('cannot yet use trend mapping for CAR1 dynamics',
+         call. = FALSE)
+  }
+
   # Ensure series and time variables are present
   data_train <- validate_series_time(data_train, name = 'data',
                                      trend_model = orig_trend_model)
diff --git a/R/validations.R b/R/validations.R
index 50574a81..e83b17fd 100644
--- a/R/validations.R
+++ b/R/validations.R
@@ -666,12 +666,6 @@ validate_trendmap = function(trend_map,
          call. = FALSE)
   }
 
-  # Cannot yet map observations to trends that evolve as CAR1
-  if(trend_model == 'CAR1'){
-    stop('cannot yet use trend mapping for CAR1 dynamics',
-         call. = FALSE)
-  }
-
   # trend_map must have an entry for each unique time series
   if(!all(sort(trend_map$series) == sort(unique(data_train$series)))){
     stop('Argument "trend_map" must have an entry for every unique time series in "data"',
diff --git a/tests/testthat/test-mvgam.R b/tests/testthat/test-mvgam.R
index b2eb6387..c43346c0 100644
--- a/tests/testthat/test-mvgam.R
+++ b/tests/testthat/test-mvgam.R
@@ -401,7 +401,6 @@ test_that("prior_only works", {
                          mod$model_file, fixed = TRUE)))
   expect_true(!any(grepl('flat_ys ~ ',
                          mod$model_file, fixed = TRUE)))
-
   mod <- mvgam(y ~ 1,
                trend_formula = ~ s(season) + s(trend, bs = 're'),
                trend_model = CAR(),
@@ -416,6 +415,20 @@ test_that("prior_only works", {
   expect_true(!any(grepl('flat_ys ~ ',
                          mod$model_file, fixed = TRUE)))
 
+  # trend_map not yet allowed for CAR1 dynamics
+  trend_map <- data.frame(series = unique(gaus_data$data_train$series),
+                          trend = c(1, 1, 2))
+  expect_error(mvgam(y ~ 1,
+                     trend_formula = ~ s(season) + s(trend, bs = 're'),
+                     trend_model = CAR(),
+                     trend_map = trend_map,
+                     data = gaus_data$data_train,
+                     prior_simulation = TRUE,
+                     family = gaussian(),
+                     threads = 2,
+                     run_model = FALSE),
+               'cannot yet use trend mapping for CAR1 dynamics')
+
   mod <- mvgam(y ~ s(season),
                trend_model = AR(p = 3),
                data = beta_data$data_train,