diff --git a/signer/rules/rules_test.go b/signer/rules/rules_test.go
index 19d9049c72..95379086a9 100644
--- a/signer/rules/rules_test.go
+++ b/signer/rules/rules_test.go
@@ -178,7 +178,7 @@ func TestSignTxRequest(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	fmt.Printf("to %v", to.Address().String())
+	t.Logf("to %v", to.Address().String())
 	resp, err := r.ApproveTx(&core.SignTxRequest{
 		Transaction: core.SendTxArgs{
 			From: *from,
@@ -294,7 +294,7 @@ func TestMissingFunc(t *testing.T) {
 	if approved {
 		t.Errorf("Expected missing method to cause non-approval")
 	}
-	fmt.Printf("Err %v", err)
+	t.Logf("Err %v", err)
 
 }
 func TestStorage(t *testing.T) {
@@ -347,7 +347,7 @@ func TestStorage(t *testing.T) {
 	if retval != exp {
 		t.Errorf("Unexpected data, expected '%v', got '%v'", exp, retval)
 	}
-	fmt.Printf("Err %v", err)
+	t.Logf("Err %v", err)
 
 }
 
@@ -605,7 +605,7 @@ function ApproveSignData(r){
 	hash, rawdata := accounts.TextAndHash([]byte(message))
 	addr, _ := mixAddr("0x694267f14675d7e1b9494fd8d72fefe1755710fa")
 
-	fmt.Printf("address %v %v\n", addr.String(), addr.Original())
+	t.Logf("address %v %v\n", addr.String(), addr.Original())
 
 	nvt := []*core.NameValueType{
 		{
diff --git a/signer/storage/aes_gcm_storage_test.go b/signer/storage/aes_gcm_storage_test.go
index a421a8449d..dbda6ee594 100644
--- a/signer/storage/aes_gcm_storage_test.go
+++ b/signer/storage/aes_gcm_storage_test.go
@@ -38,13 +38,13 @@ func TestEncryption(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	fmt.Printf("Ciphertext %x, nonce %x\n", c, iv)
+	t.Logf("Ciphertext %x, nonce %x\n", c, iv)
 
 	p, err := decrypt(key, iv, c, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
-	fmt.Printf("Plaintext %v\n", string(p))
+	t.Logf("Plaintext %v\n", string(p))
 	if !bytes.Equal(plaintext, p) {
 		t.Errorf("Failed: expected plaintext recovery, got %v expected %v", string(plaintext), string(p))
 	}