diff --git a/pkg/parser/schema_location_test.go b/pkg/parser/schema_location_test.go
index 0aea58410b4..6a3076fd374 100644
--- a/pkg/parser/schema_location_test.go
+++ b/pkg/parser/schema_location_test.go
@@ -250,6 +250,81 @@ func TestValidateMainWorkflowFrontmatterWithSchemaAndLocation_AdditionalProperti
 			wantErr:     true,
 			errContains: "/test/workflow.md:2:1:",
 		},
+		{
+			name: "workflow_call input typo now fails with additional property error",
+			frontmatter: map[string]any{
+				"on": map[string]any{
+					"workflow_call": map[string]any{
+						"inputs": map[string]any{
+							"payload": map[string]any{
+								"type":    "string",
+								"requird": true,
+							},
+						},
+					},
+				},
+			},
+			filePath:    "/test/workflow.md",
+			wantErr:     true,
+			errContains: "requird",
+		},
+		{
+			name: "workflow_call secret typo now fails with additional property error",
+			frontmatter: map[string]any{
+				"on": map[string]any{
+					"workflow_call": map[string]any{
+						"secrets": map[string]any{
+							"token": map[string]any{
+								"requird": true,
+							},
+						},
+					},
+				},
+			},
+			filePath:    "/test/workflow.md",
+			wantErr:     true,
+			errContains: "requird",
+		},
+		{
+			name: "dispatch_repository input typo now fails with additional property error",
+			frontmatter: map[string]any{
+				"on": "workflow_dispatch",
+				"safe-outputs": map[string]any{
+					"dispatch_repository": map[string]any{
+						"relay": map[string]any{
+							"event_type": "dispatch",
+							"repository": "github/gh-aw",
+							"inputs": map[string]any{
+								"payload": map[string]any{
+									"type":    "string",
+									"requird": true,
+								},
+							},
+						},
+					},
+				},
+			},
+			filePath:    "/test/workflow.md",
+			wantErr:     true,
+			errContains: "requird",
+		},
+		{
+			name: "valid workflow_call input still compiles",
+			frontmatter: map[string]any{
+				"on": map[string]any{
+					"workflow_call": map[string]any{
+						"inputs": map[string]any{
+							"payload": map[string]any{
+								"type":     "string",
+								"required": true,
+							},
+						},
+					},
+				},
+			},
+			filePath: "/test/workflow.md",
+			wantErr:  false,
+		},
 	}
 
 	for _, tt := range tests {
diff --git a/pkg/parser/schema_test.go b/pkg/parser/schema_test.go
index 9d3072713ac..6d9a67d58d2 100644
--- a/pkg/parser/schema_test.go
+++ b/pkg/parser/schema_test.go
@@ -540,6 +540,83 @@ func TestMainWorkflowSchema_WorkflowDispatchNumberTypeDocumentation(t *testing.T
 	}
 }
 
+func TestMainWorkflowSchema_WorkflowCallAndDispatchInputDefsDisallowUnknownKeys(t *testing.T) {
+	t.Parallel()
+
+	schemaContent, err := os.ReadFile("schemas/main_workflow_schema.json")
+	if err != nil {
+		t.Fatalf("failed to read schema: %v", err)
+	}
+
+	var schema map[string]any
+	if err := json.Unmarshal(schemaContent, &schema); err != nil {
+		t.Fatalf("failed to parse schema json: %v", err)
+	}
+
+	getMapAtPath := func(t *testing.T, root map[string]any, path ...any) map[string]any {
+		t.Helper()
+		var cur any = root
+		for _, p := range path {
+			switch step := p.(type) {
+			case string:
+				m, ok := cur.(map[string]any)
+				if !ok {
+					t.Fatalf("expected map before key %q", step)
+				}
+				next, ok := m[step]
+				if !ok {
+					t.Fatalf("missing key %q in path", step)
+				}
+				cur = next
+			case int:
+				arr, ok := cur.([]any)
+				if !ok {
+					t.Fatalf("expected array before index %d", step)
+				}
+				if step < 0 || step >= len(arr) {
+					t.Fatalf("index %d out of range in path", step)
+				}
+				cur = arr[step]
+			default:
+				t.Fatalf("unsupported path step type %T", p)
+			}
+		}
+
+		out, ok := cur.(map[string]any)
+		if !ok {
+			t.Fatalf("expected map at target path, got %T", cur)
+		}
+		return out
+	}
+
+	paths := []struct {
+		name string
+		path []any
+	}{
+		{
+			name: "on.workflow_call.inputs.<id>",
+			path: []any{"properties", "on", "oneOf", 1, "properties", "workflow_call", "oneOf", 1, "properties", "inputs", "additionalProperties"},
+		},
+		{
+			name: "on.workflow_call.secrets.<id>",
+			path: []any{"properties", "on", "oneOf", 1, "properties", "workflow_call", "oneOf", 1, "properties", "secrets", "additionalProperties"},
+		},
+		{
+			name: "safe-outputs.dispatch_repository.<tool>.inputs.<id>",
+			path: []any{"properties", "safe-outputs", "properties", "dispatch_repository", "additionalProperties", "properties", "inputs", "additionalProperties"},
+		},
+	}
+
+	for _, tc := range paths {
+		t.Run(tc.name, func(t *testing.T) {
+			subschema := getMapAtPath(t, schema, tc.path...)
+			if subschema["additionalProperties"] != false {
+				t.Fatalf("%s should set additionalProperties to false", tc.name)
+			}
+		})
+	}
+}
+
 func TestMainWorkflowSchema_CreatePullRequestAllowedBaseBranches(t *testing.T) {
 	t.Parallel()
 
diff --git a/pkg/parser/schemas/main_workflow_schema.json b/pkg/parser/schemas/main_workflow_schema.json
index d38819964db..c742b6c31f4 100644
--- a/pkg/parser/schemas/main_workflow_schema.json
+++ b/pkg/parser/schemas/main_workflow_schema.json
@@ -1637,7 +1637,8 @@
                           "default": {
                             "description": "Default value for the input parameter"
                           }
-                        }
+                        },
+                        "additionalProperties": false
                       }
                     },
                     "secrets": {
@@ -1654,7 +1655,8 @@
                             "type": "boolean",
                             "description": "Whether the secret is required"
                           }
-                        }
+                        },
+                        "additionalProperties": false
                       }
                     }
                   }
@@ -8411,7 +8413,8 @@
                         "type": "string"
                       }
                     }
-                  }
+                  },
+                  "additionalProperties": false
                 }
               },
               "max": {