diff --git a/d2compiler/compile.go b/d2compiler/compile.go
index 9ef9c3937..4718636c5 100644
--- a/d2compiler/compile.go
+++ b/d2compiler/compile.go
@@ -886,6 +886,10 @@ func (c *compiler) validateKey(obj *d2graph.Object, f *d2ir.Field) {
 			if !in && arrowheadIn {
 				c.errorf(f.LastPrimaryKey(), fmt.Sprintf(`invalid shape, can only set "%s" for arrowheads`, obj.Shape.Value))
 			}
+		case "constraint":
+			if obj.Shape.Value != d2target.ShapeSQLTable {
+				c.errorf(f.LastPrimaryKey(), `"constraint" keyword can only be used in "sql_table" shapes`)
+			}
 		}
 		return
 	}
diff --git a/d2compiler/compile_test.go b/d2compiler/compile_test.go
index 1ecd7ff30..19f41a60b 100644
--- a/d2compiler/compile_test.go
+++ b/d2compiler/compile_test.go
@@ -2117,9 +2117,7 @@ ok: {
   label: bar
   constraint: BIZ
 }`,
-			assertions: func(t *testing.T, g *d2graph.Graph) {
-				assert.String(t, "bar", g.Objects[0].Label.Value)
-			},
+			expErr: `d2/testdata/d2compiler/TestCompile/constraint_label.d2:3:3: "constraint" keyword can only be used in "sql_table" shapes`,
 		},
 		{
 			name: "invalid_direction",
diff --git a/testdata/d2compiler/TestCompile/constraint_label.exp.json b/testdata/d2compiler/TestCompile/constraint_label.exp.json
index ddc5dcdea..a866cd12c 100644
--- a/testdata/d2compiler/TestCompile/constraint_label.exp.json
+++ b/testdata/d2compiler/TestCompile/constraint_label.exp.json
@@ -1,180 +1,11 @@
 {
-  "graph": {
-    "name": "",
-    "isFolderOnly": false,
-    "ast": {
-      "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,0:0:0-3:1:38",
-      "nodes": [
-        {
-          "map_key": {
-            "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,0:0:0-3:1:38",
-            "key": {
-              "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,0:0:0-0:3:3",
-              "path": [
-                {
-                  "unquoted_string": {
-                    "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,0:0:0-0:3:3",
-                    "value": [
-                      {
-                        "string": "foo",
-                        "raw_string": "foo"
-                      }
-                    ]
-                  }
-                }
-              ]
-            },
-            "primary": {},
-            "value": {
-              "map": {
-                "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,0:4:4-3:1:38",
-                "nodes": [
-                  {
-                    "map_key": {
-                      "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,1:2:8-1:12:18",
-                      "key": {
-                        "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,1:2:8-1:7:13",
-                        "path": [
-                          {
-                            "unquoted_string": {
-                              "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,1:2:8-1:7:13",
-                              "value": [
-                                {
-                                  "string": "label",
-                                  "raw_string": "label"
-                                }
-                              ]
-                            }
-                          }
-                        ]
-                      },
-                      "primary": {},
-                      "value": {
-                        "unquoted_string": {
-                          "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,1:9:15-1:12:18",
-                          "value": [
-                            {
-                              "string": "bar",
-                              "raw_string": "bar"
-                            }
-                          ]
-                        }
-                      }
-                    }
-                  },
-                  {
-                    "map_key": {
-                      "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,2:2:21-2:17:36",
-                      "key": {
-                        "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,2:2:21-2:12:31",
-                        "path": [
-                          {
-                            "unquoted_string": {
-                              "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,2:2:21-2:12:31",
-                              "value": [
-                                {
-                                  "string": "constraint",
-                                  "raw_string": "constraint"
-                                }
-                              ]
-                            }
-                          }
-                        ]
-                      },
-                      "primary": {},
-                      "value": {
-                        "unquoted_string": {
-                          "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,2:14:33-2:17:36",
-                          "value": [
-                            {
-                              "string": "BIZ",
-                              "raw_string": "BIZ"
-                            }
-                          ]
-                        }
-                      }
-                    }
-                  }
-                ]
-              }
-            }
-          }
-        }
-      ]
-    },
-    "root": {
-      "id": "",
-      "id_val": "",
-      "attributes": {
-        "label": {
-          "value": ""
-        },
-        "labelDimensions": {
-          "width": 0,
-          "height": 0
-        },
-        "style": {},
-        "near_key": null,
-        "shape": {
-          "value": ""
-        },
-        "direction": {
-          "value": ""
-        },
-        "constraint": null
-      },
-      "zIndex": 0
-    },
-    "edges": null,
-    "objects": [
+  "graph": null,
+  "err": {
+    "errs": [
       {
-        "id": "foo",
-        "id_val": "foo",
-        "references": [
-          {
-            "key": {
-              "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,0:0:0-0:3:3",
-              "path": [
-                {
-                  "unquoted_string": {
-                    "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,0:0:0-0:3:3",
-                    "value": [
-                      {
-                        "string": "foo",
-                        "raw_string": "foo"
-                      }
-                    ]
-                  }
-                }
-              ]
-            },
-            "key_path_index": 0,
-            "map_key_edge_index": -1
-          }
-        ],
-        "attributes": {
-          "label": {
-            "value": "bar"
-          },
-          "labelDimensions": {
-            "width": 0,
-            "height": 0
-          },
-          "style": {},
-          "near_key": null,
-          "shape": {
-            "value": "rectangle"
-          },
-          "direction": {
-            "value": ""
-          },
-          "constraint": [
-            "BIZ"
-          ]
-        },
-        "zIndex": 0
+        "range": "d2/testdata/d2compiler/TestCompile/constraint_label.d2,2:2:21-2:17:36",
+        "errmsg": "d2/testdata/d2compiler/TestCompile/constraint_label.d2:3:3: \"constraint\" keyword can only be used in \"sql_table\" shapes"
       }
     ]
-  },
-  "err": null
+  }
 }