diff --git a/src/coreclr/jit/lower.cpp b/src/coreclr/jit/lower.cpp
index 30880e1969bdfc..c9754f5437c450 100644
--- a/src/coreclr/jit/lower.cpp
+++ b/src/coreclr/jit/lower.cpp
@@ -5217,13 +5217,10 @@ bool Lowering::LowerUnsignedDivOrMod(GenTreeOp* divMod)
 
         unsigned bits = type == TYP_INT ? 32 : 64;
         // if the dividend operand is AND or RSZ with a constant then the number of input bits can be reduced
-        if (dividend->OperIs(GT_AND))
+        if (dividend->OperIs(GT_AND) && dividend->gtGetOp2()->IsCnsIntOrI())
         {
-            size_t maskCns = static_cast<size_t>(
-                dividend->gtGetOp1()->IsCnsIntOrI()
-                    ? dividend->gtGetOp1()->AsIntCon()->IconValue()
-                    : dividend->gtGetOp2()->IsCnsIntOrI() ? dividend->gtGetOp2()->AsIntCon()->IconValue() : 0);
-            if (maskCns)
+            size_t maskCns = static_cast<size_t>(dividend->gtGetOp2()->AsIntCon()->IconValue());
+            if (maskCns != 0)
             {
                 unsigned maskBits = 1;
                 while (maskCns >>= 1)
@@ -5236,7 +5233,9 @@ bool Lowering::LowerUnsignedDivOrMod(GenTreeOp* divMod)
         {
             size_t shiftCns = static_cast<size_t>(dividend->gtGetOp2()->AsIntCon()->IconValue());
             if (shiftCns < bits)
+            {
                 bits -= static_cast<unsigned>(shiftCns);
+            }
         }
 
         if (type == TYP_INT)
diff --git a/src/coreclr/jit/utils.cpp b/src/coreclr/jit/utils.cpp
index d5b7da8c829795..e454eb338682bc 100644
--- a/src/coreclr/jit/utils.cpp
+++ b/src/coreclr/jit/utils.cpp
@@ -2417,6 +2417,7 @@ T GetUnsignedMagic(T d, bool* increment /*out*/, int* preShift /*out*/, int* pos
 uint32_t GetUnsigned32Magic(
     uint32_t d, bool* increment /*out*/, int* preShift /*out*/, int* postShift /*out*/, unsigned bits)
 {
+    assert(bits <= 32);
     return GetUnsignedMagic<uint32_t>(d, increment, preShift, postShift, bits);
 }
 
@@ -2424,6 +2425,7 @@ uint32_t GetUnsigned32Magic(
 uint64_t GetUnsigned64Magic(
     uint64_t d, bool* increment /*out*/, int* preShift /*out*/, int* postShift /*out*/, unsigned bits)
 {
+    assert(bits <= 64);
     return GetUnsignedMagic<uint64_t>(d, increment, preShift, postShift, bits);
 }
 #endif
diff --git a/src/coreclr/jit/utils.h b/src/coreclr/jit/utils.h
index 6ed392ab2b16f9..44521010288426 100644
--- a/src/coreclr/jit/utils.h
+++ b/src/coreclr/jit/utils.h
@@ -762,10 +762,10 @@ class CritSecHolder
 namespace MagicDivide
 {
 uint32_t GetUnsigned32Magic(
-    uint32_t d, bool* increment /*out*/, int* preShift /*out*/, int* postShift /*out*/, unsigned bits = 32);
+    uint32_t d, bool* increment /*out*/, int* preShift /*out*/, int* postShift /*out*/, unsigned bits);
 #ifdef TARGET_64BIT
 uint64_t GetUnsigned64Magic(
-    uint64_t d, bool* increment /*out*/, int* preShift /*out*/, int* postShift /*out*/, unsigned bits = 64);
+    uint64_t d, bool* increment /*out*/, int* preShift /*out*/, int* postShift /*out*/, unsigned bits);
 #endif
 int32_t GetSigned32Magic(int32_t d, int* shift /*out*/);
 #ifdef TARGET_64BIT