diff --git a/apps/server/src/routes/api/llm.spec.ts b/apps/server/src/routes/api/llm.spec.ts
index a1f1ca3c2..846b9ecc9 100644
--- a/apps/server/src/routes/api/llm.spec.ts
+++ b/apps/server/src/routes/api/llm.spec.ts
@@ -52,9 +52,9 @@ vi.mock("../../services/llm/ai_service_manager.js", () => ({
 
 // Mock chat pipeline
 const mockChatPipelineExecute = vi.fn();
-const MockChatPipeline = vi.fn().mockImplementation(function () {
-    this.execute = mockChatPipelineExecute;
-});
+class MockChatPipeline {
+    execute = mockChatPipelineExecute;
+}
 vi.mock("../../services/llm/pipeline/chat_pipeline.js", () => ({
     ChatPipeline: MockChatPipeline
 }));
diff --git a/apps/server/src/services/llm/ai_service_manager.spec.ts b/apps/server/src/services/llm/ai_service_manager.spec.ts
index 47c43c36e..bea473913 100644
--- a/apps/server/src/services/llm/ai_service_manager.spec.ts
+++ b/apps/server/src/services/llm/ai_service_manager.spec.ts
@@ -34,26 +34,29 @@ vi.mock('../log.js', () => ({
     }
 }));
 
-vi.mock('./providers/anthropic_service.js', () => ({
-    AnthropicService: vi.fn().mockImplementation(function () {
-        this.isAvailable = vi.fn().mockReturnValue(true);
-        this.generateChatCompletion = vi.fn();
-    })
-}));
+vi.mock('./providers/anthropic_service.js', () => {
+    class AnthropicService {
+        isAvailable = vi.fn().mockReturnValue(true);
+        generateChatCompletion = vi.fn();
+    }
+    return { AnthropicService };
+});
 
-vi.mock('./providers/openai_service.js', () => ({
-    OpenAIService: vi.fn().mockImplementation(function () {
-        this.isAvailable = vi.fn().mockReturnValue(true);
-        this.generateChatCompletion = vi.fn();
-    })
-}));
+vi.mock('./providers/openai_service.js', () => {
+    class OpenAIService {
+        isAvailable = vi.fn().mockReturnValue(true);
+        generateChatCompletion = vi.fn();
+    }
+    return { OpenAIService };
+});
 
-vi.mock('./providers/ollama_service.js', () => ({
-    OllamaService: vi.fn().mockImplementation(function () {
-        this.isAvailable = vi.fn().mockReturnValue(true);
-        this.generateChatCompletion = vi.fn();
-    })
-}));
+vi.mock('./providers/ollama_service.js', () => {
+    class OllamaService {
+        isAvailable = vi.fn().mockReturnValue(true);
+        generateChatCompletion = vi.fn();
+    }
+    return { OllamaService };
+});
 
 vi.mock('./config/configuration_helpers.js', () => ({
     getSelectedProvider: vi.fn(),
diff --git a/apps/server/src/services/llm/chat/rest_chat_service.spec.ts b/apps/server/src/services/llm/chat/rest_chat_service.spec.ts
index d0ba94617..c797c290b 100644
--- a/apps/server/src/services/llm/chat/rest_chat_service.spec.ts
+++ b/apps/server/src/services/llm/chat/rest_chat_service.spec.ts
@@ -38,11 +38,12 @@ vi.mock('../pipeline/chat_pipeline.js', () => ({
     }))
 }));
 
-vi.mock('./handlers/tool_handler.js', () => ({
-    ToolHandler: vi.fn().mockImplementation(function () {
-        this.handleToolCalls = vi.fn()
-    })
-}));
+vi.mock('./handlers/tool_handler.js', () => {
+    class ToolHandler {
+        handleToolCalls = vi.fn()
+    }
+    return { ToolHandler };
+});
 
 vi.mock('../chat_storage_service.js', () => ({
     default: {
diff --git a/apps/server/src/services/llm/chat_service.spec.ts b/apps/server/src/services/llm/chat_service.spec.ts
index c9d491057..578fc03da 100644
--- a/apps/server/src/services/llm/chat_service.spec.ts
+++ b/apps/server/src/services/llm/chat_service.spec.ts
@@ -35,24 +35,28 @@ vi.mock('./constants/llm_prompt_constants.js', () => ({
     }
 }));
 
-vi.mock('./pipeline/chat_pipeline.js', () => ({
-    ChatPipeline: vi.fn().mockImplementation(function (config) {
-        Object.assign(this, {
-            config,
-            execute: vi.fn(),
-            getMetrics: vi.fn(),
-            resetMetrics: vi.fn(),
-            stages: {
-                contextExtraction: {
-                    execute: vi.fn()
-                },
-                semanticContextExtraction: {
-                    execute: vi.fn()
-                }
+vi.mock('./pipeline/chat_pipeline.js', () => {
+    class ChatPipeline {
+        config: any;
+
+        constructor(config: any) {
+            this.config = config;
+        }
+
+        execute = vi.fn();
+        getMetrics = vi.fn();
+        resetMetrics = vi.fn();
+        stages = {
+            contextExtraction: {
+                execute: vi.fn()
+            },
+            semanticContextExtraction: {
+                execute: vi.fn()
             }
-        });
-    })
-}));
+        }
+    }
+    return { ChatPipeline };
+});
 
 vi.mock('./ai_service_manager.js', () => ({
     default: {
diff --git a/apps/server/src/services/llm/context/services/context_service.spec.ts b/apps/server/src/services/llm/context/services/context_service.spec.ts
index 486ec7179..66dce8e9f 100644
--- a/apps/server/src/services/llm/context/services/context_service.spec.ts
+++ b/apps/server/src/services/llm/context/services/context_service.spec.ts
@@ -46,11 +46,12 @@ vi.mock('../../ai_service_manager.js', () => ({
     }
 }));
 
-vi.mock('../index.js', () => ({
-    ContextExtractor: vi.fn().mockImplementation(function () {
-        this.findRelevantNotes = vi.fn().mockResolvedValue([])
-    })
-}));
+vi.mock('../index.js', () => {
+    class ContextExtractor {
+        findRelevantNotes = vi.fn().mockResolvedValue([])
+    }
+    return { ContextExtractor };
+});
 
 describe('ContextService', () => {
     let service: ContextService;
diff --git a/apps/server/src/services/llm/providers/anthropic_service.spec.ts b/apps/server/src/services/llm/providers/anthropic_service.spec.ts
index df48c1339..5a4e8b8e3 100644
--- a/apps/server/src/services/llm/providers/anthropic_service.spec.ts
+++ b/apps/server/src/services/llm/providers/anthropic_service.spec.ts
@@ -48,8 +48,8 @@ vi.mock('@anthropic-ai/sdk', () => {
         }
     };
 
-    const mockAnthropic = vi.fn().mockImplementation(function () {
-        this.messages = {
+    class MockAnthropic {
+        messages = {
             create: vi.fn().mockImplementation((params) => {
                 if (params.stream) {
                     return Promise.resolve(mockStream);
@@ -72,9 +72,9 @@ vi.mock('@anthropic-ai/sdk', () => {
                 });
             })
         };
-    });
+    }
 
-    return { default: mockAnthropic };
+    return { default: MockAnthropic };
 });
 
 describe('AnthropicService', () => {
diff --git a/apps/server/src/services/llm/providers/ollama_service.spec.ts b/apps/server/src/services/llm/providers/ollama_service.spec.ts
index 46b8072ea..2d4072742 100644
--- a/apps/server/src/services/llm/providers/ollama_service.spec.ts
+++ b/apps/server/src/services/llm/providers/ollama_service.spec.ts
@@ -29,12 +29,12 @@ vi.mock('./providers.js', () => ({
     getOllamaOptions: vi.fn()
 }));
 
-vi.mock('../formatters/ollama_formatter.js', () => ({
-    OllamaMessageFormatter: vi.fn().mockImplementation(function () {
-        this.formatMessages = vi.fn().mockReturnValue([
+vi.mock('../formatters/ollama_formatter.js', () => {
+    class MockFormatter {
+        formatMessages = vi.fn().mockReturnValue([
             { role: 'user', content: 'Hello' }
         ]);
-        this.formatResponse = vi.fn().mockReturnValue({
+        formatResponse = vi.fn().mockReturnValue({
             text: 'Hello! How can I help you today?',
             provider: 'Ollama',
             model: 'llama2',
@@ -45,8 +45,9 @@ vi.mock('../formatters/ollama_formatter.js', () => ({
             },
             tool_calls: null
         });
-    })
-}));
+    }
+    return { OllamaMessageFormatter: MockFormatter };
+});
 
 vi.mock('../tools/tool_registry.js', () => ({
     default: {
@@ -83,8 +84,8 @@ vi.mock('ollama', () => {
         }
     };
 
-    const mockOllama = vi.fn().mockImplementation(function () {
-        this.chat = vi.fn().mockImplementation((params) => {
+    class MockOllama {
+        chat = vi.fn().mockImplementation((params) => {
             if (params.stream) {
                 return Promise.resolve(mockStream);
             }
@@ -98,7 +99,7 @@ vi.mock('ollama', () => {
                 done: true
             });
         });
-        this.show = vi.fn().mockResolvedValue({
+        show = vi.fn().mockResolvedValue({
             modelfile: 'FROM llama2',
             parameters: {},
             template: '',
@@ -110,7 +111,7 @@ vi.mock('ollama', () => {
                 quantization_level: 'Q4_0'
             }
         });
-        this.list = vi.fn().mockResolvedValue({
+        list = vi.fn().mockResolvedValue({
             models: [
                 {
                     name: 'llama2:latest',
@@ -118,10 +119,10 @@ vi.mock('ollama', () => {
                     size: 3800000000
                 }
             ]
-        })
-    });
+        });
+    }
 
-    return { Ollama: mockOllama };
+    return { Ollama: MockOllama };
 });
 
 // Mock global fetch