diff --git a/tests/draft2019-09/optional/format/uri.json b/tests/draft2019-09/optional/format/uri.json
index 25cc40c8..4306a686 100644
--- a/tests/draft2019-09/optional/format/uri.json
+++ b/tests/draft2019-09/optional/format/uri.json
@@ -97,6 +97,11 @@
                 "description": "an invalid URI with spaces and missing scheme",
                 "data": ":// should fail",
                 "valid": false
+            },
+            {
+                "description": "an invalid URI with comma in scheme",
+                "data": "bar,baz:foo",
+                "valid": false
             }
         ]
     }
diff --git a/tests/draft4/optional/format/uri.json b/tests/draft4/optional/format/uri.json
index 25cc40c8..4306a686 100644
--- a/tests/draft4/optional/format/uri.json
+++ b/tests/draft4/optional/format/uri.json
@@ -97,6 +97,11 @@
                 "description": "an invalid URI with spaces and missing scheme",
                 "data": ":// should fail",
                 "valid": false
+            },
+            {
+                "description": "an invalid URI with comma in scheme",
+                "data": "bar,baz:foo",
+                "valid": false
             }
         ]
     }
diff --git a/tests/draft6/optional/format/uri.json b/tests/draft6/optional/format/uri.json
index 25cc40c8..4306a686 100644
--- a/tests/draft6/optional/format/uri.json
+++ b/tests/draft6/optional/format/uri.json
@@ -97,6 +97,11 @@
                 "description": "an invalid URI with spaces and missing scheme",
                 "data": ":// should fail",
                 "valid": false
+            },
+            {
+                "description": "an invalid URI with comma in scheme",
+                "data": "bar,baz:foo",
+                "valid": false
             }
         ]
     }
diff --git a/tests/draft7/optional/format/uri.json b/tests/draft7/optional/format/uri.json
index 25cc40c8..4306a686 100644
--- a/tests/draft7/optional/format/uri.json
+++ b/tests/draft7/optional/format/uri.json
@@ -97,6 +97,11 @@
                 "description": "an invalid URI with spaces and missing scheme",
                 "data": ":// should fail",
                 "valid": false
+            },
+            {
+                "description": "an invalid URI with comma in scheme",
+                "data": "bar,baz:foo",
+                "valid": false
             }
         ]
     }