diff --git a/model/renderers/olmo3_test.go b/model/renderers/olmo3_test.go
index bd1f717dc..31384d1fc 100644
--- a/model/renderers/olmo3_test.go
+++ b/model/renderers/olmo3_test.go
@@ -227,9 +227,9 @@ func TestOlmo3Renderer(t *testing.T) {
 							ID: "call_1",
 							Function: api.ToolCallFunction{
 								Name: "book_flight",
-								Arguments: testArgs(map[string]any{
-									"from": "SFO",
-									"to":   "NYC",
+								Arguments: testArgsOrdered([]orderedArg{
+									{"from", "SFO"},
+									{"to", "NYC"},
 								}),
 							},
 						},
@@ -243,9 +243,9 @@ func TestOlmo3Renderer(t *testing.T) {
 						Name: "book_flight",
 						Parameters: api.ToolFunctionParameters{
 							Type: "object",
-							Properties: testPropsMap(map[string]api.ToolProperty{
-								"from": {Type: api.PropertyType{"string"}},
-								"to":   {Type: api.PropertyType{"string"}},
+							Properties: testPropsOrdered([]orderedProp{
+								{"from", api.ToolProperty{Type: api.PropertyType{"string"}}},
+								{"to", api.ToolProperty{Type: api.PropertyType{"string"}}},
 							}),
 						},
 					},
diff --git a/model/renderers/testhelpers_test.go b/model/renderers/testhelpers_test.go
index 6eac8eee4..8b628e1a9 100644
--- a/model/renderers/testhelpers_test.go
+++ b/model/renderers/testhelpers_test.go
@@ -34,3 +34,18 @@ func testArgsOrdered(pairs []orderedArg) api.ToolCallFunctionArguments {
 	}
 	return args
 }
+
+// orderedProp represents a key-value pair for ordered property creation
+type orderedProp struct {
+	Key   string
+	Value api.ToolProperty
+}
+
+// testPropsOrdered creates a ToolPropertiesMap with a specific key order
+func testPropsOrdered(pairs []orderedProp) *api.ToolPropertiesMap {
+	props := api.NewToolPropertiesMap()
+	for _, p := range pairs {
+		props.Set(p.Key, p.Value)
+	}
+	return props
+}