diff --git a/.clang-tidy b/.clang-tidy
index ac526f193c..df924ca6a8 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -2,4 +2,5 @@ Checks: [-*,
          bugprone-assignment-in-if-condition,
          bugprone-branch-clone,
          bugprone-implicit-widening-of-multiplication-result,
+         bugprone-incorrect-division,
 ]
diff --git a/src/RandTest.cc b/src/RandTest.cc
index 3e94dd5556..9d53ddefe3 100644
--- a/src/RandTest.cc
+++ b/src/RandTest.cc
@@ -60,7 +60,7 @@ void RandTest::add(const void* buf, int bufl) {
             montey = 0;
             for ( int mj = 0; mj < RT_MONTEN / 2; mj++ ) {
                 montex = (montex * 256.0) + monte[mj];
-                montey = (montey * 256.0) + monte[(RT_MONTEN / 2) + mj];
+                montey = (montey * 256.0) + monte[static_cast<size_t>((RT_MONTEN / 2) + mj)];
             }
             if ( montex * montex + montey * montey <= RT_INCIRC ) {
                 inmont++;
diff --git a/src/RandTest.h b/src/RandTest.h
index e1f0682fe5..f422cdbbe3 100644
--- a/src/RandTest.h
+++ b/src/RandTest.h
@@ -4,11 +4,9 @@
 
 #include <cstdint>
 
-#define RT_MONTEN                                                                                                      \
-    6 /* Bytes used as Monte Carlo                                                                                     \
-         co-ordinates. This should be no more                                                                          \
-         bits than the mantissa of your "double"                                                                       \
-         floating point type. */
+// Bytes used as Monte Carlo co-ordinates. This should be no more bits than the mantissa
+// of your "double" floating point type.
+constexpr int RT_MONTEN = 6;
 
 namespace zeek {