diff --git a/src/common.h b/src/common.h
index 1514369d15..d4af04aa32 100644
--- a/src/common.h
+++ b/src/common.h
@@ -59,6 +59,8 @@ typedef uint64_t uintptr_t;
 #    error "unsupported architecture"
 #  endif
 
+typedef intptr_t alias_t;
+
 #else // not _MSC_VER
 
 #  include "stdint.h"
@@ -86,6 +88,8 @@ typedef uint64_t uintptr_t;
 #    error "unsupported architecture"
 #  endif
 
+typedef intptr_t __attribute__((__may_alias__)) alias_t;
+
 #endif // not _MSC_VER
 
 #undef JNIEXPORT
diff --git a/src/machine.cpp b/src/machine.cpp
index 92cca91a1b..4933d30f7c 100644
--- a/src/machine.cpp
+++ b/src/machine.cpp
@@ -2145,8 +2145,8 @@ class HeapClient: public Heap::Client {
     memcpy(dst, src, n * BytesPerWord);
 
     if (hashTaken(t, src)) {
-      cast<uintptr_t>(dst, 0) &= PointerMask;
-      cast<uintptr_t>(dst, 0) |= ExtendedMark;
+      cast<alias_t>(dst, 0) &= PointerMask;
+      cast<alias_t>(dst, 0) |= ExtendedMark;
       extendedWord(t, dst, base) = takeHash(t, src);
     }
   }
@@ -2781,7 +2781,7 @@ allocate3(Thread* t, Allocator* allocator, Machine::AllocationType type,
 
     memset(o, 0, sizeInBytes);
 
-    cast<uintptr_t>(o, 0) = FixedMark;
+    cast<alias_t>(o, 0) = FixedMark;
 
     t->m->fixedFootprint += total;
 
@@ -2796,7 +2796,7 @@ allocate3(Thread* t, Allocator* allocator, Machine::AllocationType type,
 
     memset(o, 0, sizeInBytes);
 
-    cast<uintptr_t>(o, 0) = FixedMark;
+    cast<alias_t>(o, 0) = FixedMark;
 
     return o;
   }
diff --git a/src/machine.h b/src/machine.h
index 3c152223ab..78ce6d5448 100644
--- a/src/machine.h
+++ b/src/machine.h
@@ -1878,8 +1878,8 @@ setObjectClass(Thread*, object o, object value)
 {
   cast<object>(o, 0)
     = reinterpret_cast<object>
-    (reinterpret_cast<uintptr_t>(value)
-     | (reinterpret_cast<uintptr_t>(cast<object>(o, 0)) & (~PointerMask)));
+    (reinterpret_cast<alias_t>(value)
+     | (reinterpret_cast<alias_t>(cast<object>(o, 0)) & (~PointerMask)));
 }
 
 inline const char*
@@ -2094,19 +2094,19 @@ setType(Thread* t, Machine::Type type, object value)
 inline bool
 objectFixed(Thread*, object o)
 {
-  return (cast<uintptr_t>(o, 0) & (~PointerMask)) == FixedMark;
+  return (cast<alias_t>(o, 0) & (~PointerMask)) == FixedMark;
 }
 
 inline bool
 objectExtended(Thread*, object o)
 {
-  return (cast<uintptr_t>(o, 0) & (~PointerMask)) == ExtendedMark;
+  return (cast<alias_t>(o, 0) & (~PointerMask)) == ExtendedMark;
 }
 
 inline bool
 hashTaken(Thread*, object o)
 {
-  return (cast<uintptr_t>(o, 0) & (~PointerMask)) == HashTakenMark;
+  return (cast<alias_t>(o, 0) & (~PointerMask)) == HashTakenMark;
 }
 
 inline unsigned
@@ -2237,7 +2237,7 @@ markHashTaken(Thread* t, object o)
 
   ACQUIRE_RAW(t, t->m->heapLock);
 
-  cast<uintptr_t>(o, 0) |= HashTakenMark;
+  cast<alias_t>(o, 0) |= HashTakenMark;
   t->m->heap->pad(o);
 }
 
diff --git a/src/util.cpp b/src/util.cpp
index 511389ade8..7ae8de1217 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -66,32 +66,32 @@ inline object
 getTreeNodeValue(Thread*, object n)
 {
   return reinterpret_cast<object>
-    (cast<intptr_t>(n, TreeNodeValue) & PointerMask);
+    (cast<alias_t>(n, TreeNodeValue) & PointerMask);
 }
 
 inline void
 setTreeNodeValue(Thread* t, object n, object value)
 {
-  intptr_t red = cast<intptr_t>(n, TreeNodeValue) & (~PointerMask);
+  alias_t red = cast<alias_t>(n, TreeNodeValue) & (~PointerMask);
 
   set(t, n, TreeNodeValue, value);
 
-  cast<intptr_t>(n, TreeNodeValue) |= red;
+  cast<alias_t>(n, TreeNodeValue) |= red;
 }
 
 inline bool
 treeNodeRed(Thread*, object n)
 {
-  return (cast<intptr_t>(n, TreeNodeValue) & (~PointerMask)) == 1;
+  return (cast<alias_t>(n, TreeNodeValue) & (~PointerMask)) == 1;
 }
 
 inline void
 setTreeNodeRed(Thread*, object n, bool red)
 {
   if (red) {
-    cast<intptr_t>(n, TreeNodeValue) |= 1;
+    cast<alias_t>(n, TreeNodeValue) |= 1;
   } else {
-    cast<intptr_t>(n, TreeNodeValue) &= PointerMask;
+    cast<alias_t>(n, TreeNodeValue) &= PointerMask;
   }
 }
 
@@ -108,7 +108,7 @@ cloneTreeNode(Thread* t, object n)
 
 object
 treeFind(Thread* t, object tree, intptr_t key, object sentinal,
-          intptr_t (*compare)(Thread* t, intptr_t key, object b))
+         intptr_t (*compare)(Thread* t, intptr_t key, object b))
 {
   object node = tree;
   while (node != sentinal) {
@@ -140,6 +140,7 @@ treeFind(Thread* t, TreeContext* c, object old, intptr_t key, object node,
   object new_ = newRoot;
   PROTECT(t, new_);
 
+  int count = 0;
   while (old != sentinal) {
     c->ancestors = path(c, new_, c->ancestors);
 
@@ -162,6 +163,13 @@ treeFind(Thread* t, TreeContext* c, object old, intptr_t key, object node,
       c->ancestors = c->ancestors->next;
       return;
     }
+
+    if (++ count > 100) {
+      // if we've gone this deep, we probably have an unbalanced tree,
+      // which should only happen if there's a serious bug somewhere
+      // in our insertion process
+      abort(t);
+    }
   }
 
   setTreeNodeValue(t, new_, getTreeNodeValue(t, node));