diff --git a/R/fcast.R b/R/fcast.R
index a35095ae0..cce593213 100644
--- a/R/fcast.R
+++ b/R/fcast.R
@@ -64,7 +64,7 @@ split_deparsing = function(expr, varnames, LHSallvars, RHSallvars) {
     }
     this
   })
-  lvars = lapply(lvars, function(x) if (length(x) && !is.list(x)) list(x) else unique(x))
+  lvars = lapply(lvars, function(x) if (length(x) && !is.list(x)) list(x) else tryCatch(unique(x), error = function(e) x))
 }
 
 deparse_formula = function(expr, varnames, allvars) {
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 62eca23c8..2804cdfbf 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -3673,6 +3673,8 @@ test(1100, dt1[dt2,roll=-Inf,rollends=c(FALSE,TRUE)]$ind, INT(NA,NA,1,2,2,2,2,2,
   DT2 = data.table(index = c("a","b"), x = 1:2, y = rnorm(2))
   DT3 = data.table(year = c(rep(1986,4), rep(1987,3), rep(1988,2), 1989:1991), continent = rep(c("Europe","Asia"), each = 6), country = rep(c("Sweden","Germany","France","India","Japan","China"), each = 2))
   DT3_dcasted = dcast(DT3, ... ~ ..., fun.aggregate = length, value.var.in.RHSdots = TRUE, value.var = "country")
+  DT3_dcasted2 = dcast(DT3, . ~ ..., fun.aggregate = length, value.var.in.RHSdots = TRUE, value.var = "country")
+  DT3_dcasted3 = dcast(DT3, 1 ~ ..., fun.aggregate = length, value.var.in.RHSdots = TRUE, value.var = "country")
   test(1102.181, dcast(DT, ... ~ index, fun.aggregate = length, value.var.in.dots = NA), error = "Argument 'value.var.in.dots' should be logical TRUE/FALSE")
   test(1102.182, dcast(DT, ... ~ index, fun.aggregate = length, value.var.in.LHSdots = NA), error = "Arguments 'value.var.in.LHSdots', 'value.var.in.RHSdots' should be logical TRUE/FALSE")
   test(1102.183, dcast(DT, ... ~ index, fun.aggregate = length, value.var.in.dots = TRUE), data.table(x = 1:2, a = 1:0, b = 0:1, key = "x"))
@@ -3681,6 +3683,9 @@ test(1100, dt1[dt2,roll=-Inf,rollends=c(FALSE,TRUE)]$ind, INT(NA,NA,1,2,2,2,2,2,
   test(1102.186, names(dcast(DT2, ... ~ ..., value.var = "y", value.var.in.LHSdots = TRUE)), c("index", "x", "y", "a_1", "b_2"))
   test(1102.187, dim(DT3_dcasted), c(7L,11L))
   test(1102.188, names(DT3_dcasted), c("year", "continent", "1986_Europe_Germany", "1986_Europe_Sweden", "1987_Asia_India", "1987_Europe_France", "1988_Asia_India", "1988_Asia_Japan", "1989_Asia_Japan", "1990_Asia_China", "1991_Asia_China"))
+  test(1102.189, DT3_dcasted2, DT3_dcasted3)
+  test(1102.1891, dim(DT3_dcasted2), c(1L,10L))
+  test(1102.1892, names(DT3_dcasted2), c(".", "1986_Europe_Germany", "1986_Europe_Sweden", "1987_Asia_India", "1987_Europe_France", "1988_Asia_India", "1988_Asia_Japan", "1989_Asia_Japan", "1990_Asia_China", "1991_Asia_China"))
 
 
   # bug git #693 - dcast error message improvement: