diff --git a/src/proxy/tinymitm/ssl.cpp b/src/proxy/tinymitm/ssl.cpp
index fd9d633..8cf3406 100644
--- a/src/proxy/tinymitm/ssl.cpp
+++ b/src/proxy/tinymitm/ssl.cpp
@@ -103,7 +103,17 @@ bool CertificateManager::installCertificate()
     bool success = false;
     if (rootStore)
     {
-        success = CertAddCertificateContextToStore(rootStore, certCtx, CERT_STORE_ADD_REPLACE_EXISTING, NULL);
+        PCCERT_CONTEXT existingCert = CertFindCertificateInStore(rootStore, X509_ASN_ENCODING | PKCS_7_ASN_ENCODING, 0,
+                                                                 CERT_FIND_EXISTING, certCtx, NULL);
+        if (existingCert)
+        {
+            CertFreeCertificateContext(existingCert);
+            success = true;
+        }
+        else
+        {
+            success = CertAddCertificateContextToStore(rootStore, certCtx, CERT_STORE_ADD_REPLACE_EXISTING, NULL);
+        }
         CertCloseStore(rootStore, 0);
     }
     CertFreeCertificateContext(certCtx);