diff --git a/.clang-tidy b/.clang-tidy
index cf85fa8..3542c7f 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -16,6 +16,7 @@
 bugprone-fold-init-type,
 bugprone-forward-declaration-namespace,
 bugprone-forwarding-reference-overload,
+bugprone-implicit-widening-of-multiplication-result,
 bugprone-inaccurate-erase,
 bugprone-inc-dec-in-conditions,
 bugprone-incorrect-enable-if,
diff --git a/certificate.cpp b/certificate.cpp
index 5e4ef9c..0ff3ad5 100644
--- a/certificate.cpp
+++ b/certificate.cpp
@@ -549,7 +549,7 @@
     // Set time to 00:00am GMT, Jan 1 1970; format: YYYYMMDDHHMMSSZ
     ASN1_TIME_set_string(epoch.get(), "19700101000000Z");
 
-    static const uint64_t dayToSeconds = 24 * 60 * 60;
+    constexpr uint64_t dayToSeconds = 86400; // 24 * 60 * 60
     ASN1_TIME* notAfter = X509_get_notAfter(&cert);
     ASN1_TIME_diff(&days, &secs, epoch.get(), notAfter);
     validNotAfter((days * dayToSeconds) + secs);