diff --git a/src/NodeParser/IndexedAccessTypeNodeParser.ts b/src/NodeParser/IndexedAccessTypeNodeParser.ts
index d7a481350..0a5445a06 100644
--- a/src/NodeParser/IndexedAccessTypeNodeParser.ts
+++ b/src/NodeParser/IndexedAccessTypeNodeParser.ts
@@ -1,4 +1,5 @@
 import ts from "typescript";
+import { LogicError } from "../Error/Errors.js";
 import type { Context, NodeParser } from "../NodeParser.js";
 import type { SubNodeParser } from "../SubNodeParser.js";
 import type { BaseType } from "../Type/BaseType.js";
@@ -9,9 +10,9 @@ import { ReferenceType } from "../Type/ReferenceType.js";
 import { StringType } from "../Type/StringType.js";
 import { TupleType } from "../Type/TupleType.js";
 import { UnionType } from "../Type/UnionType.js";
+import { isErroredUnknownType } from "../Type/UnknownType.js";
 import { derefType } from "../Utils/derefType.js";
 import { getTypeByKey } from "../Utils/typeKeys.js";
-import { LogicError } from "../Error/Errors.js";
 
 export class IndexedAccessTypeNodeParser implements SubNodeParser {
     public constructor(
@@ -49,7 +50,7 @@ export class IndexedAccessTypeNodeParser implements SubNodeParser {
         const indexType = derefType(this.childNodeParser.createType(node.indexType, context));
         const indexedType = this.createIndexedType(node.objectType, context, indexType);
 
-        if (indexedType) {
+        if (indexedType && !isErroredUnknownType(indexedType)) {
             return indexedType;
         }
 
diff --git a/src/NodeParser/TypeReferenceNodeParser.ts b/src/NodeParser/TypeReferenceNodeParser.ts
index 14535a243..559260d5c 100644
--- a/src/NodeParser/TypeReferenceNodeParser.ts
+++ b/src/NodeParser/TypeReferenceNodeParser.ts
@@ -6,6 +6,7 @@ import { AnyType } from "../Type/AnyType.js";
 import { ArrayType } from "../Type/ArrayType.js";
 import type { BaseType } from "../Type/BaseType.js";
 import { StringType } from "../Type/StringType.js";
+import { UnknownType } from "../Type/UnknownType.js";
 import { symbolAtNode } from "../Utils/symbolAtNode.js";
 
 const invalidTypes: Record<number, boolean> = {
@@ -45,7 +46,7 @@ export class TypeReferenceNodeParser implements SubNodeParser {
         }
 
         if (typeSymbol.flags & ts.SymbolFlags.TypeParameter) {
-            return context.getArgument(typeSymbol.name);
+            return context.getArgument(typeSymbol.name) || new UnknownType(true);
         }
 
         // Wraps promise type to avoid resolving to a empty Object type.
diff --git a/src/Type/UnknownType.ts b/src/Type/UnknownType.ts
index 6cce276ff..78004074f 100644
--- a/src/Type/UnknownType.ts
+++ b/src/Type/UnknownType.ts
@@ -1,10 +1,23 @@
 import { BaseType } from "./BaseType.js";
 
 export class UnknownType extends BaseType {
-    constructor() {
+    constructor(
+        /**
+         * If the source for this UnknownType was from a failed operation than to an actual `unknown` type present in the source code.
+         */
+        readonly erroredSource = false,
+    ) {
         super();
     }
+
     public getId(): string {
         return "unknown";
     }
 }
+
+/**
+ * Checks for an UnknownType with an errored source.
+ */
+export function isErroredUnknownType(type: BaseType): type is UnknownType {
+    return type instanceof UnknownType && type.erroredSource;
+}