diff --git a/src/core/checkedint.d b/src/core/checkedint.d
index b474e141ce..99096fa1c4 100644
--- a/src/core/checkedint.d
+++ b/src/core/checkedint.d
@@ -168,9 +168,7 @@ pragma(inline, true)
 uint addu()(uint x, uint y, ref bool overflow)
 {
     immutable uint r = x + y;
-    immutable bool o = r < x;
-    assert(o == (r < y));
-    if (o)
+    if (r < x || r < y)
         overflow = true;
     return r;
 }
@@ -179,14 +177,6 @@ uint addu()(uint x, uint y, ref bool overflow)
 @betterC
 unittest
 {
-    for (uint i = 0; i < 10; ++i)
-    {
-        bool overflow;
-        immutable uint r = addu (uint.max - i, uint.max - i, overflow);
-        assert (r == 2 * (uint.max - i));
-        assert (overflow);
-    }
-
     bool overflow;
     assert(addu(2, 3, overflow) == 5);
     assert(!overflow);
@@ -213,9 +203,7 @@ pragma(inline, true)
 ulong addu()(ulong x, ulong y, ref bool overflow)
 {
     immutable ulong r = x + y;
-    immutable bool o = r < x;
-    assert(o == (r < y));
-    if (o)
+    if (r < x || r < y)
         overflow = true;
     return r;
 }
@@ -252,9 +240,7 @@ pragma(inline, true)
 ucent addu()(ucent x, ucent y, ref bool overflow)
 {
     immutable ucent r = x + y;
-    immutable bool o = r < x;
-    assert(o == (r < y));
-    if (o)
+    if (r < x || r < y)
         overflow = true;
     return r;
 }