diff --git a/R/datasets.R b/R/datasets.R
index 5297101..e978122 100644
--- a/R/datasets.R
+++ b/R/datasets.R
@@ -23,6 +23,7 @@ match_datasets <- function(ds) {
 #' @examples
 #' abbreviate_datasets(c("flywire", "flywire", "hemibrain"))
 abbreviate_datasets <- function(ds) {
+  if(length(ds)<1) return(ds)
   ds=match_datasets(ds)
   abbrevlist=c(hemibrain='hb', flywire='fw', manc='mv', fanc='fv', malecns='mc',
                opticlobe='ol', banc='bc')
diff --git a/R/partners.R b/R/partners.R
index 745169c..4c95a7c 100644
--- a/R/partners.R
+++ b/R/partners.R
@@ -143,12 +143,22 @@ cf_partners <- function(ids, threshold=1L, partners=c("inputs", "outputs"),
         ))
     }
     tres=coconat:::standardise_partner_summary(tres)
-    tres$dataset=n
+    if(nrow(tres)>0) {
+      tres$dataset=n
+    } else {
+      tres$dataset=character()
+      warning("no ", partners, " found for `", n, "` dataset.")
+    }
     tres$pre_key=keys(tres, idcol="pre_id")
     tres$post_key=keys(tres, idcol='post_id')
     res[[n]]=tres
   }
-  if(isTRUE(bind.rows)) bind_rows2(res) else res
+  if(isTRUE(bind.rows)) {
+    res=bind_rows2(res)
+    # record the datasets we tried to find
+    attr(res, 'datasets')=names(ids)
+    res
+  } else res
 }
 
 
diff --git a/tests/testthat/test-cosine.R b/tests/testthat/test-cosine.R
index 3a1d1b4..06cd1ce 100644
--- a/tests/testthat/test-cosine.R
+++ b/tests/testthat/test-cosine.R
@@ -33,3 +33,15 @@ test_that("cosine plots work", {
       expect_equal(cf_cosine_plot(lalids, min_datasets = 1, heatmap = F),
                    hc1)))
 })
+
+
+test_that("cosine plot with no partners", {
+  op <- options(fafbseg.use_static_celltypes=T)
+  on.exit(options(op))
+
+  suppressWarnings(
+    suppressMessages(
+      expect_warning(cf_cosine_plot(cf_ids(hemibrain = 'ORN_DA1', flywire = 'ORN_DA1'), threshold = 8),
+                     "no inputs.*flywire")
+    ))
+})