diff --git a/src/mutators/builtIn/fixIncompleteTypes/fixIncompleteInterfaceOrTypeLiteralGenerics/collectGenericNodeReferences.ts b/src/mutators/builtIn/fixIncompleteTypes/fixIncompleteInterfaceOrTypeLiteralGenerics/collectGenericNodeReferences.ts
index d0228db784..0f3bdfb3d7 100644
--- a/src/mutators/builtIn/fixIncompleteTypes/fixIncompleteInterfaceOrTypeLiteralGenerics/collectGenericNodeReferences.ts
+++ b/src/mutators/builtIn/fixIncompleteTypes/fixIncompleteInterfaceOrTypeLiteralGenerics/collectGenericNodeReferences.ts
@@ -4,8 +4,8 @@ import { FileMutationsRequest } from "../../../../shared/fileMutator.js";
 import {
 	getIdentifyingTypeLiteralParent,
 	isNodeWithDefinedTypeArguments,
-	isNodeWithDefinedTypeParameters,
 	isNodeWithIdentifierName,
+	isNodeWithTypeParameters,
 } from "../../../../shared/nodeTypes.js";
 import { isTypeArgumentsType } from "../../../../shared/typeNodes.js";
 import { getTypeAtLocationIfNotError } from "../../../../shared/types.js";
@@ -84,8 +84,9 @@ export const expandReferencesForGenericTypes = (
 		const templatedDeclaration = templatedDeclarationSymbol.valueDeclaration;
 		if (
 			templatedDeclaration === undefined ||
-			!isNodeWithDefinedTypeParameters(templatedDeclaration) ||
-			templatedParentInstantiation.typeArguments === undefined
+			!isNodeWithTypeParameters(templatedDeclaration) ||
+			templatedParentInstantiation.typeArguments === undefined ||
+			templatedDeclaration.typeParameters === undefined
 		) {
 			continue;
 		}
diff --git a/src/shared/nodeTypes.ts b/src/shared/nodeTypes.ts
index 12a0004d89..1fef825a78 100644
--- a/src/shared/nodeTypes.ts
+++ b/src/shared/nodeTypes.ts
@@ -64,8 +64,8 @@ export type NodeWithDefinedTypeArguments = ts.Node & {
 
 // TODO: make this a more specific type
 // Will have to deal with instantiations (new Container<T>() { ... }) and declarations (class Container<T>() { ... }))
-export type NodeWithDefinedTypeParameters = ts.Node & {
-	typeParameters: ts.NodeArray<ts.TypeNode>;
+export type NodeWithTypeParameters = ts.Node & {
+	typeParameters: ts.NodeArray<ts.TypeNode> | undefined;
 };
 
 export const isNodeWithType = (
@@ -84,9 +84,9 @@ export const isNodeWithDefinedTypeArguments = (
 	return "typeArguments" in node;
 };
 
-export const isNodeWithDefinedTypeParameters = (
+export const isNodeWithTypeParameters = (
 	node: ts.Node,
-): node is NodeWithDefinedTypeParameters => {
+): node is NodeWithTypeParameters => {
 	return "typeParameters" in node;
 };
 
diff --git a/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/expected.ts b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/expected.ts
new file mode 100644
index 0000000000..9004c7f943
--- /dev/null
+++ b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/expected.ts
@@ -0,0 +1,7 @@
+(function () {
+	interface Shape {
+		value?: unknown;
+	}
+
+	[].reduce<Shape>(() => ({}), {});
+})();
diff --git a/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/original.ts b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/original.ts
new file mode 100644
index 0000000000..9004c7f943
--- /dev/null
+++ b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/original.ts
@@ -0,0 +1,7 @@
+(function () {
+	interface Shape {
+		value?: unknown;
+	}
+
+	[].reduce<Shape>(() => ({}), {});
+})();
diff --git a/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/tsconfig.json b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/tsconfig.json
new file mode 100644
index 0000000000..7de2b9de32
--- /dev/null
+++ b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/tsconfig.json
@@ -0,0 +1,3 @@
+{
+	"files": ["actual.ts"]
+}
diff --git a/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/typestat.json b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/typestat.json
new file mode 100644
index 0000000000..1406ae0fa5
--- /dev/null
+++ b/test/cases/fixes/incompleteTypes/nonGenericInterfaceAsTypeArgument/typestat.json
@@ -0,0 +1,5 @@
+{
+	"fixes": {
+		"incompleteTypes": true
+	}
+}