diff --git a/encoding/jsonschema/testdata/txtar/pattern_with_empty_field.txtar b/encoding/jsonschema/testdata/txtar/pattern_with_empty_field.txtar
new file mode 100644
index 00000000000..d310cadd17f
--- /dev/null
+++ b/encoding/jsonschema/testdata/txtar/pattern_with_empty_field.txtar
@@ -0,0 +1,21 @@
+# This tests the case where there's a patternProperties keyword
+# and no other fields.
+# TODO the empty-field test should fail but currently does not.
+
+-- schema.json --
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "object",
+    "patternProperties": {
+    	".*": {
+    		"type": "string"
+    	}
+    }
+}
+-- out/decode/extract --
+@jsonschema(schema="https://json-schema.org/draft/2020-12/schema")
+
+{[=~".*" & !~"^()$"]: string}
+...
+-- test/empty-field.json --
+{"": true}