diff --git a/pkg/bifs/collections.go b/pkg/bifs/collections.go
index cd3f87da2..a47730702 100644
--- a/pkg/bifs/collections.go
+++ b/pkg/bifs/collections.go
@@ -373,7 +373,7 @@ func BIF_joink(input1, input2 *mlrval.Mlrval) *mlrval.Mlrval {
 // joinv([3,4,5], ",") -> "3,4,5"
 // joinv({"a":3,"b":4,"c":5}, ",") -> "3,4,5"
 func BIF_joinv(input1, input2 *mlrval.Mlrval) *mlrval.Mlrval {
-	if !input2.IsString() {
+	if !input2.IsStringOrVoid() {
 		return mlrval.FromNotStringError("joinv", input2)
 	}
 	fieldSeparator := input2.AcquireStringValue()
diff --git a/test/cases/dsl-split-join/0028/cmd b/test/cases/dsl-split-join/0028/cmd
new file mode 100644
index 000000000..6add080d4
--- /dev/null
+++ b/test/cases/dsl-split-join/0028/cmd
@@ -0,0 +1 @@
+mlr -n put -f ${CASEDIR}/mlr
diff --git a/test/cases/dsl-split-join/0028/experr b/test/cases/dsl-split-join/0028/experr
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/cases/dsl-split-join/0028/expout b/test/cases/dsl-split-join/0028/expout
new file mode 100644
index 000000000..51b400812
--- /dev/null
+++ b/test/cases/dsl-split-join/0028/expout
@@ -0,0 +1 @@
+345
diff --git a/test/cases/dsl-split-join/0028/mlr b/test/cases/dsl-split-join/0028/mlr
new file mode 100644
index 000000000..08e79d8dc
--- /dev/null
+++ b/test/cases/dsl-split-join/0028/mlr
@@ -0,0 +1 @@
+end {print joinv([3,4,5], "")}