diff --git a/jsonschema/containsref_test.go b/jsonschema/containsref_test.go
new file mode 100644
index 000000000..dc1842775
--- /dev/null
+++ b/jsonschema/containsref_test.go
@@ -0,0 +1,48 @@
+package jsonschema_test
+
+import (
+	"testing"
+
+	"github.com/sashabaranov/go-openai/jsonschema"
+)
+
+// SelfRef struct used to produce a self-referential schema.
+type SelfRef struct {
+	Friends []SelfRef `json:"friends"`
+}
+
+// Address struct referenced by Person without self-reference.
+type Address struct {
+	Street string `json:"street"`
+}
+
+type Person struct {
+	Address Address `json:"address"`
+}
+
+// TestGenerateSchemaForType_SelfRef ensures that self-referential types are not
+// flattened during schema generation.
+func TestGenerateSchemaForType_SelfRef(t *testing.T) {
+	schema, err := jsonschema.GenerateSchemaForType(SelfRef{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if _, ok := schema.Defs["SelfRef"]; !ok {
+		t.Fatal("expected defs to contain SelfRef for self reference")
+	}
+}
+
+// TestGenerateSchemaForType_NoSelfRef ensures that non-self-referential types
+// are flattened and do not reappear in $defs.
+func TestGenerateSchemaForType_NoSelfRef(t *testing.T) {
+	schema, err := jsonschema.GenerateSchemaForType(Person{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if _, ok := schema.Defs["Person"]; ok {
+		t.Fatal("unexpected Person definition in defs")
+	}
+	if _, ok := schema.Defs["Address"]; !ok {
+		t.Fatal("expected Address definition in defs")
+	}
+}
diff --git a/jsonschema/json_errors_test.go b/jsonschema/json_errors_test.go
new file mode 100644
index 000000000..3b864fc21
--- /dev/null
+++ b/jsonschema/json_errors_test.go
@@ -0,0 +1,27 @@
+package jsonschema_test
+
+import (
+	"testing"
+
+	"github.com/sashabaranov/go-openai/jsonschema"
+)
+
+// TestGenerateSchemaForType_ErrorPaths verifies error handling for unsupported types.
+func TestGenerateSchemaForType_ErrorPaths(t *testing.T) {
+	type anon struct{ Ch chan int }
+	tests := []struct {
+		name string
+		v    any
+	}{
+		{"slice", []chan int{}},
+		{"anon struct", anon{}},
+		{"pointer", (*chan int)(nil)},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if _, err := jsonschema.GenerateSchemaForType(tt.v); err == nil {
+				t.Errorf("expected error for %s", tt.name)
+			}
+		})
+	}
+}