2 files changed, 3 insertions, 0 deletions
diff --git a/NEWS.md b/NEWS.md
index 68d5a394..8e6ed11f 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -6,6 +6,8 @@
 
 - Add plots to `compiled_models` vignette
 
+- Give an explanatory error message when mkinmod fails due to a missing definition of a target variable
+
 ## mkin 0.9-41 (2015-11-09)
 
 ### Minor changes
diff --git a/R/mkinmod.R b/R/mkinmod.R
index f98a3803..c70f1260 100644
--- a/R/mkinmod.R
+++ b/R/mkinmod.R
@@ -180,6 +180,7 @@ mkinmod <- function(..., use_of_ff = "min", speclist = NULL, quiet = FALSE, verb
 
       # Add transfer terms to listed compartments
       for (target in to) {
+        if (!target %in% obs_vars) stop("You did not specify a submodel for target variable ", target)
         target_box <- switch(spec[[target]]$type,
           SFO = target,
           IORE = target,