diff --git a/runtime/vam/expr/cast/bool.go b/runtime/vam/expr/cast/bool.go
index e2404d125..6c44c1ccc 100644
--- a/runtime/vam/expr/cast/bool.go
+++ b/runtime/vam/expr/cast/bool.go
@@ -15,6 +15,12 @@ func castToBool(vec vector.Any, index []uint32) (vector.Any, []uint32, string, b
 		out = numberToBool(vec.Values, index)
 	case *vector.Float:
 		out = numberToBool(vec.Values, index)
+	case *vector.Bool:
+		out := vector.Any(vec)
+		if index != nil {
+			out = vector.Pick(out, index)
+		}
+		return out, nil, "", true
 	case *vector.String:
 		vvec, errs := stringToBool(vec, index)
 		return vvec, errs, "", true
diff --git a/runtime/ztests/expr/cast/bool.yaml b/runtime/ztests/expr/cast/bool.yaml
index 5315df1a3..a270ec717 100644
--- a/runtime/ztests/expr/cast/bool.yaml
+++ b/runtime/ztests/expr/cast/bool.yaml
@@ -3,6 +3,10 @@ spq: this::bool
 vector: true
 
 input: |
+  true
+  false
+  null::bool
+  null
   1
   0
   24::uint8
@@ -20,6 +24,10 @@ input: |
   "1"
 
 output: |
+  true
+  false
+  null::bool
+  null::bool
   true
   false
   true