diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index 32b7233344..2d23a40665 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -4428,6 +4428,10 @@ public function addTypeToExpression(Expr $expr, Type $type): self
 
 		if ($originalExprType->equals($nativeType)) {
 			$newType = TypeCombinator::intersect($type, $originalExprType);
+			if ($newType->isConstantScalarValue()->yes() && $newType->equals($originalExprType)) {
+				// don't add the same type over and over again to improve performance
+				return $this;
+			}
 			return $this->specifyExpressionType($expr, $newType, $newType, TrinaryLogic::createYes());
 		}
 
diff --git a/tests/PHPStan/Analyser/AnalyserIntegrationTest.php b/tests/PHPStan/Analyser/AnalyserIntegrationTest.php
index e00c33313d..e8bbb0d1fd 100644
--- a/tests/PHPStan/Analyser/AnalyserIntegrationTest.php
+++ b/tests/PHPStan/Analyser/AnalyserIntegrationTest.php
@@ -1554,6 +1554,12 @@ public function testBug12787(): void
 		$this->assertNoErrors($errors);
 	}
 
+	public function testBug12800(): void
+	{
+		$errors = $this->runAnalyse(__DIR__ . '/data/bug-12800.php');
+		$this->assertNoErrors($errors);
+	}
+
 	/**
 	 * @param string[]|null $allAnalysedFiles
 	 * @return Error[]
diff --git a/tests/PHPStan/Analyser/data/bug-12800.php b/tests/PHPStan/Analyser/data/bug-12800.php
new file mode 100644
index 0000000000..66d362f527
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/bug-12800.php
@@ -0,0 +1,123 @@
+<?php
+
+namespace Bug12800;
+
+class a
+{
+	/**
+	 * @param array<mixed> $labels
+	 */
+	public function b(array $labels, \stdClass $payment): bool
+	{
+		$fullData = '
+        {
+            "additionalData": {
+                "acquirerAccountCode": "TestPmmAcquirerAccount",
+                "authorisationMid": "1009",
+                "cvcResult": "1 Matches",
+                "avsResult": "4 AVS not supported for this card type",
+                "authCode": "25595",
+                "acquirerReference": "acquirerReference",
+                "expiryDate": "8/2018",
+                "avsResultRaw": "Y",
+                "cvcResultRaw": "M",
+                "refusalReasonRaw": "00 : Approved or completed successfully",
+                "refusalCodeRaw": "00",
+                "acquirerCode": "TestPmmAcquirer",
+                "inferredRefusalReason": "3D Secure Mandated",
+                "networkTxReference": "MCC123456789012",
+                "cardHolderName": "Test Cardholder",
+                "issuerCountry": "NL",
+                "countryCode": "NL",
+                "cardBin": "411111",
+                "issuerBin": "41111101",
+                "cardSchemeCommercial": "true",
+                "cardPaymentMethod": "visa",
+                "cardIssuingBank": "Bank of America",
+                "cardIssuingCountry": "US",
+                "cardIssuingCurrency": "USD",
+                "fundingSource": "PREPAID_RELOADABLE",
+                "cardSummary": "1111",
+                "isCardCommercial": "true",
+                "paymentMethodVariant": "visadebit",
+                "paymentMethod": "visa",
+                "coBrandedWith": "visa",
+                "businessTypeIdentifier": "PP",
+                "cardProductId": "P",
+                "bankSummary": "1111",
+                "bankAccount.ownerName": "A. Klaassen",
+                "bankAccount.iban": "NL13TEST0123456789",
+                "cavv": "AQIDBAUGBw",
+                "xid": "ODgxNDc2MDg2",
+                "cavvAlgorithm": "3",
+                "eci": "02",
+                "dsTransID": "f8062b92-66e9-4c5a-979a-f465e66a6e48",
+                "threeDSVersion": "2.1.0",
+                "threeDAuthenticatedResponse": "Y",
+                "liabilityShift": "true",
+                "threeDOffered": "true",
+                "threeDAuthenticated": "false",
+                "challengeCancel": "01",
+                "fraudResultType": "FRAUD",
+                "fraudManualReview": "false"
+            },
+            "fraudResult": {
+                "accountScore": 10,
+                "result": {
+                    "fraudCheckResult": {
+                        "accountScore": "10",
+                        "checkId": "26",
+                        "name": "ShopperEmailRefCheck"
+                    }
+                }
+            },
+         "response": "[cancelOrRefund-received]"
+        }';
+
+		$result = json_decode($fullData, true);
+
+		$r = $labels['result_code'] === ''
+			&& $labels['merchant_reference'] === $payment->merchant_reference
+			&& $labels['brand_code'] === $payment->brand_code
+			&& $labels['acquirer_account_code'] === $result['additionalData']['acquirerAccountCode']
+			&& $labels['authorisation_mid'] === $result['additionalData']['authorisationMid']
+			&& $labels['cvc_result'] === $result['additionalData']['cvcResult']
+			&& $labels['auth_code'] === $result['additionalData']['authCode']
+			&& $labels['acquirer_reference'] === $result['additionalData']['acquirerReference']
+			&& $labels['expiry_date'] === $result['additionalData']['expiryDate']
+			&& $labels['avs_result_raw'] === $result['additionalData']['avsResultRaw']
+			&& $labels['cvc_result_raw'] === $result['additionalData']['cvcResultRaw']
+			&& $labels['acquirer_code'] === $result['additionalData']['acquirerCode']
+			&& $labels['inferred_refusal_reason'] === $result['additionalData']['inferredRefusalReason']
+			&& $labels['network_tx_reference'] === $result['additionalData']['networkTxReference']
+			&& $labels['issuer_country'] === $result['additionalData']['issuerCountry']
+			&& $labels['country_code'] === $result['additionalData']['countryCode']
+			&& $labels['card_bin'] === $result['additionalData']['cardBin']
+			&& $labels['issuer_bin'] === $result['additionalData']['issuerBin']
+			&& $labels['card_scheme_commercial'] === $result['additionalData']['cardSchemeCommercial']
+			&& $labels['card_payment_method'] === $result['additionalData']['cardPaymentMethod']
+			&& $labels['card_issuing_bank'] === $result['additionalData']['cardIssuingBank']
+			&& $labels['card_issuing_country'] === $result['additionalData']['cardIssuingCountry']
+			&& $labels['card_issuing_currency'] === $result['additionalData']['cardIssuingCurrency']
+			&& $labels['card_summary'] === $result['additionalData']['cardSummary']
+			&& $labels['payment_method_variant'] === $result['additionalData']['paymentMethodVariant']
+			&& $labels['payment_method'] === $result['additionalData']['paymentMethod']
+			&& $labels['co_branded_with'] === $result['additionalData']['coBrandedWith']
+			&& $labels['business_type_identifier'] === $result['additionalData']['businessTypeIdentifier']
+			&& $labels['card_product_id'] === $result['additionalData']['cardProductId']
+			&& $labels['bank_summary'] === $result['additionalData']['bankSummary']
+			&& $labels['cavv'] === $result['additionalData']['cavv']
+			&& $labels['xid'] === $result['additionalData']['xid']
+			&& $labels['cavv_algorithm'] === $result['additionalData']['cavvAlgorithm']
+			&& $labels['eci'] === $result['additionalData']['eci']
+			&& $labels['ds_trans_id'] === $result['additionalData']['dsTransID']
+			&& $labels['liability_shift'] === $result['additionalData']['liabilityShift']
+			&& $labels['fraud_result_type'] === $result['additionalData']['fraudResultType']
+			&& $labels['fraud_manual_review'] === $result['additionalData']['fraudManualReview']
+			&& $labels['fraud_result_account_score'] === $result['fraudResult']['accountScore']
+			&& $labels['fraud_result_check_id'] === $result['fraudResult']['result']['fraudCheckResult']['checkId']
+			&& $labels['fraud_result_name'] === $result['fraudResult']['result']['fraudCheckResult']['name']
+			&& $labels['response'] === $result['response'];
+		return $r;
+	}
+}