diff --git a/Controller/Payment/Setup.php b/Controller/Payment/Setup.php
index 65be86a..4d3ee87 100644
--- a/Controller/Payment/Setup.php
+++ b/Controller/Payment/Setup.php
@@ -38,9 +38,32 @@ public function execute() {
             try {
                 return $this->processAuthorization($order);
             } catch (\Pstk\Paystack\Gateway\Exception\ApiException $e) {
-                $message = $e->getMessage();
-                $order->addStatusToHistory($order->getStatus(), $message);
+                // The exception message is built from curl_error() and Paystack's raw
+                // response body (see Gateway/PaystackApiClient::request()), so it can
+                // carry internal hostnames, TLS/proxy detail, or gateway-side state —
+                // the same leak D5 closed on Callback.php. Detail stays in the
+                // (admin-only) order history; the customer gets a fixed, safe string.
+                // Context array, not string concatenation, so an embedded newline in
+                // the gateway/curl text can't forge additional log lines.
+                $this->logger->error('Paystack setup API error', [
+                    'error' => $e->getMessage(),
+                    'exception' => $e,
+                ]);
+                $order->addStatusToHistory($order->getStatus(), $e->getMessage());
                 $this->orderRepository->save($order);
+                $message = "We could not start your Paystack payment. Please try again "
+                    . "or contact support if the problem continues.";
+            } catch (\Throwable $e) {
+                // Same rationale as the ApiException branch above, for anything else
+                // processAuthorization() can throw (a missing store URL, a malformed
+                // Paystack response, a save failure) — D5's Callback.php fix added
+                // this same bare-Throwable catch for the identical reason.
+                $this->logger->error('Paystack setup failed', [
+                    'error' => $e->getMessage(),
+                    'exception' => $e,
+                ]);
+                $message = "We could not start your Paystack payment. Please try again "
+                    . "or contact support if the problem continues.";
             }
         }
 
diff --git a/Test/Unit/Controller/Payment/SetupTest.php b/Test/Unit/Controller/Payment/SetupTest.php
index 16b15c2..3f60b37 100644
--- a/Test/Unit/Controller/Payment/SetupTest.php
+++ b/Test/Unit/Controller/Payment/SetupTest.php
@@ -457,6 +457,67 @@ public function testApiExceptionSavesStatusHistory(): void
             ->method('save')
             ->with($order);
 
+        // The raw ApiException message ("Invalid key" — built from curl_error()
+        // and Paystack's raw response body in real use) must never reach the
+        // customer-facing failure page; only the fixed, safe string may.
+        $this->messageManager->expects($this->once())
+            ->method('addErrorMessage')
+            ->with($this->callback(function ($message) {
+                $text = (string) $message;
+                return !str_contains($text, 'Invalid key')
+                    && str_contains($text, 'We could not start your Paystack payment');
+            }));
+
+        $controller->execute();
+    }
+
+    public function testGenericThrowableShowsSafeMessageAndDoesNotLeakDetail(): void
+    {
+        $controller = $this->createController();
+
+        $lastOrder = $this->createMock(Order::class);
+        $lastOrder->method('getIncrementId')->willReturn('000000001');
+        $this->checkoutSession->method('getLastRealOrder')->willReturn($lastOrder);
+
+        $payment = $this->createMock(Payment::class);
+        $payment->method('getMethod')->willReturn(Paystack::CODE);
+
+        $order = $this->createMock(Order::class);
+        $order->method('getPayment')->willReturn($payment);
+        $order->method('getStatus')->willReturn('pending');
+        $order->method('getCustomerFirstname')->willReturn('John');
+        $order->method('getCustomerLastname')->willReturn('Doe');
+        $order->method('getGrandTotal')->willReturn(100.00);
+        $order->method('getCustomerEmail')->willReturn('john@test.com');
+        $order->method('getIncrementId')->willReturn('000000001');
+        $order->method('getOrderCurrencyCode')->willReturn('NGN');
+
+        $this->orderInterface->method('loadByIncrementId')->willReturn($order);
+
+        $methodInstance = $this->createMock(MethodInterface::class);
+        $methodInstance->method('getCode')->willReturn(Paystack::CODE);
+        $this->paymentHelper->method('getMethodInstance')->willReturn($methodInstance);
+
+        $store = $this->createMock(Store::class);
+        $store->method('getBaseUrl')->willReturn('https://example.com/');
+        $this->storeManager->method('getStore')->willReturn($store);
+
+        $this->transactionValidator->method('expectedSubunits')->willReturn(10000);
+
+        // A non-ApiException throwable (e.g. a malformed Paystack response, a
+        // missing store URL) must be caught too — not just ApiException — and
+        // must never surface its own message to the customer.
+        $this->paystackClient->method('initializeTransaction')
+            ->willThrowException(new \RuntimeException('unexpected internal detail'));
+
+        $this->messageManager->expects($this->once())
+            ->method('addErrorMessage')
+            ->with($this->callback(function ($message) {
+                $text = (string) $message;
+                return !str_contains($text, 'unexpected internal detail')
+                    && str_contains($text, 'We could not start your Paystack payment');
+            }));
+
         $controller->execute();
     }
 }