diff --git a/ts/provider.ollama.ts b/ts/provider.ollama.ts
index 2a58bdf..8c92292 100644
--- a/ts/provider.ollama.ts
+++ b/ts/provider.ollama.ts
@@ -345,9 +345,9 @@ export class OllamaProvider extends MultiModalModel {
     const timeout = optionsArg.timeout || this.defaultTimeout;
     const modelOptions = { ...this.defaultOptions, ...optionsArg.options };
 
-    // Format history messages with optional images and reasoning
+    // Format history messages with optional images, reasoning, and tool_calls
     const historyMessages = optionsArg.messageHistory.map((msg) => {
-      const formatted: { role: string; content: string; images?: string[]; reasoning?: string } = {
+      const formatted: { role: string; content: string; images?: string[]; reasoning?: string; tool_calls?: any[] } = {
         role: msg.role,
         content: msg.content,
       };
@@ -357,6 +357,11 @@ export class OllamaProvider extends MultiModalModel {
       if (msg.reasoning) {
         formatted.reasoning = msg.reasoning;
       }
+      // CRITICAL: Include tool_calls in history for native tool calling
+      // Without this, the model doesn't know it already called a tool and may call it again
+      if ((msg as any).tool_calls && Array.isArray((msg as any).tool_calls)) {
+        formatted.tool_calls = (msg as any).tool_calls;
+      }
       return formatted;
     });
 
@@ -494,7 +499,7 @@ export class OllamaProvider extends MultiModalModel {
     const timeout = optionsArg.timeout || this.defaultTimeout;
     const modelOptions = { ...this.defaultOptions, ...optionsArg.options };
 
-    // Format history messages with optional images, reasoning, and tool role
+    // Format history messages with optional images, reasoning, tool_calls, and tool role
     const historyMessages = optionsArg.messageHistory.map((msg) => {
       // Handle tool result messages
       if ((msg as any).role === 'tool') {
@@ -505,7 +510,7 @@ export class OllamaProvider extends MultiModalModel {
         };
       }
 
-      const formatted: { role: string; content: string; images?: string[]; reasoning?: string } = {
+      const formatted: { role: string; content: string; images?: string[]; reasoning?: string; tool_calls?: any[] } = {
         role: msg.role,
         content: msg.content,
       };
@@ -515,6 +520,11 @@ export class OllamaProvider extends MultiModalModel {
       if (msg.reasoning) {
         formatted.reasoning = msg.reasoning;
       }
+      // CRITICAL: Include tool_calls in history for native tool calling
+      // Without this, the model doesn't know it already called a tool and may call it again
+      if ((msg as any).tool_calls && Array.isArray((msg as any).tool_calls)) {
+        formatted.tool_calls = (msg as any).tool_calls;
+      }
       return formatted;
     });