diff --git a/include/avian/codegen/architecture.h b/include/avian/codegen/architecture.h
index 91a41551f0..b1cd7e8013 100644
--- a/include/avian/codegen/architecture.h
+++ b/include/avian/codegen/architecture.h
@@ -20,7 +20,7 @@ class Zone;
 namespace avian {
 
 namespace util {
-class Allocator;
+class Alloc;
 }
 
 namespace codegen {
@@ -143,7 +143,7 @@ class Architecture {
                                unsigned cSize,
                                OperandMask& cMask) = 0;
 
-  virtual Assembler* makeAssembler(util::Allocator*, vm::Zone*) = 0;
+  virtual Assembler* makeAssembler(util::Alloc*, vm::Zone*) = 0;
 
   virtual void acquire() = 0;
   virtual void release() = 0;
diff --git a/include/avian/util/slice.h b/include/avian/util/slice.h
index 13930bc8a6..a5003f1ac5 100644
--- a/include/avian/util/slice.h
+++ b/include/avian/util/slice.h
@@ -99,7 +99,7 @@ class Slice {
     return slice;
   }
 
-  void resize(Allocator* a, size_t newCount)
+  void resize(Alloc* a, size_t newCount)
   {
     Slice<T> slice(clone(a, newCount));
     a->free(items, count);
diff --git a/src/avian/alloc-vector.h b/src/avian/alloc-vector.h
index a859864d7c..29b82f1551 100644
--- a/src/avian/alloc-vector.h
+++ b/src/avian/alloc-vector.h
@@ -26,7 +26,7 @@ namespace vm {
 class Vector {
  public:
   Vector(avian::util::Aborter* a,
-         avian::util::Allocator* allocator,
+         avian::util::Alloc* allocator,
          size_t minimumCapacity)
       : a(a),
         allocator(allocator),
@@ -175,7 +175,7 @@ class Vector {
   }
 
   avian::util::Aborter* a;
-  avian::util::Allocator* allocator;
+  avian::util::Alloc* allocator;
   avian::util::Slice<uint8_t> data;
   size_t position;
   size_t minimumCapacity;
diff --git a/src/avian/lzma.h b/src/avian/lzma.h
index 12642ded3f..7d6ec23ec7 100644
--- a/src/avian/lzma.h
+++ b/src/avian/lzma.h
@@ -15,20 +15,20 @@
 
 namespace avian {
 namespace util {
-class Allocator;
+class AllocOnly;
 }
 }
 
 namespace vm {
 
 uint8_t* decodeLZMA(System* s,
-                    avian::util::Allocator* a,
+                    avian::util::AllocOnly* a,
                     uint8_t* in,
                     unsigned inSize,
                     unsigned* outSize);
 
 uint8_t* encodeLZMA(System* s,
-                    avian::util::Allocator* a,
+                    avian::util::AllocOnly* a,
                     uint8_t* in,
                     unsigned inSize,
                     unsigned* outSize);
diff --git a/src/codegen/target/arm/assembler.cpp b/src/codegen/target/arm/assembler.cpp
index 9f9b0dcfce..7de408deba 100644
--- a/src/codegen/target/arm/assembler.cpp
+++ b/src/codegen/target/arm/assembler.cpp
@@ -619,7 +619,7 @@ class MyArchitecture : public Architecture {
     }
   }
 
-  virtual Assembler* makeAssembler(Allocator* allocator, Zone* zone);
+  virtual Assembler* makeAssembler(Alloc* allocator, Zone* zone);
 
   virtual void acquire()
   {
@@ -639,7 +639,7 @@ class MyArchitecture : public Architecture {
 
 class MyAssembler : public Assembler {
  public:
-  MyAssembler(System* s, Allocator* a, Zone* zone, MyArchitecture* arch)
+  MyAssembler(System* s, Alloc* a, Zone* zone, MyArchitecture* arch)
       : con(s, a, zone), arch_(arch)
   {
   }
@@ -1075,7 +1075,7 @@ class MyAssembler : public Assembler {
   MyArchitecture* arch_;
 };
 
-Assembler* MyArchitecture::makeAssembler(Allocator* allocator, Zone* zone)
+Assembler* MyArchitecture::makeAssembler(Alloc* allocator, Zone* zone)
 {
   return new (zone) MyAssembler(this->con.s, allocator, zone, this);
 }
diff --git a/src/codegen/target/arm/context.cpp b/src/codegen/target/arm/context.cpp
index 1c2757abbc..a690caf410 100644
--- a/src/codegen/target/arm/context.cpp
+++ b/src/codegen/target/arm/context.cpp
@@ -15,7 +15,7 @@ namespace avian {
 namespace codegen {
 namespace arm {
 
-Context::Context(vm::System* s, util::Allocator* a, vm::Zone* zone)
+Context::Context(vm::System* s, util::Alloc* a, vm::Zone* zone)
     : s(s),
       zone(zone),
       client(0),
diff --git a/src/codegen/target/arm/context.h b/src/codegen/target/arm/context.h
index 15d3c2e0f0..45d937da9b 100644
--- a/src/codegen/target/arm/context.h
+++ b/src/codegen/target/arm/context.h
@@ -24,7 +24,7 @@ namespace avian {
 
 namespace util {
 class Aborter;
-class Allocator;
+class Alloc;
 }  // namespace util
 
 namespace codegen {
@@ -37,7 +37,7 @@ class ConstantPoolEntry;
 
 class Context {
  public:
-  Context(vm::System* s, util::Allocator* a, vm::Zone* zone);
+  Context(vm::System* s, util::Alloc* a, vm::Zone* zone);
 
   vm::System* s;
   vm::Zone* zone;
diff --git a/src/codegen/target/x86/assembler.cpp b/src/codegen/target/x86/assembler.cpp
index e124a97a85..e9ada91b2e 100644
--- a/src/codegen/target/x86/assembler.cpp
+++ b/src/codegen/target/x86/assembler.cpp
@@ -887,7 +887,7 @@ class MyArchitecture : public Architecture {
     }
   }
 
-  virtual Assembler* makeAssembler(util::Allocator* allocator, Zone* zone);
+  virtual Assembler* makeAssembler(util::Alloc* allocator, Zone* zone);
 
   virtual void acquire()
   {
@@ -908,7 +908,7 @@ class MyArchitecture : public Architecture {
 
 class MyAssembler : public Assembler {
  public:
-  MyAssembler(System* s, util::Allocator* a, Zone* zone, MyArchitecture* arch)
+  MyAssembler(System* s, util::Alloc* a, Zone* zone, MyArchitecture* arch)
       : c(s, a, zone, &(arch->c)), arch_(arch)
   {
   }
@@ -1273,7 +1273,7 @@ class MyAssembler : public Assembler {
   MyArchitecture* arch_;
 };
 
-Assembler* MyArchitecture::makeAssembler(util::Allocator* allocator, Zone* zone)
+Assembler* MyArchitecture::makeAssembler(util::Alloc* allocator, Zone* zone)
 {
   return new (zone) MyAssembler(c.s, allocator, zone, this);
 }
diff --git a/src/codegen/target/x86/context.cpp b/src/codegen/target/x86/context.cpp
index 93cdef29cd..c86e5734ef 100644
--- a/src/codegen/target/x86/context.cpp
+++ b/src/codegen/target/x86/context.cpp
@@ -24,7 +24,7 @@ ArchitectureContext::ArchitectureContext(vm::System* s, bool useNativeFeatures)
 }
 
 Context::Context(vm::System* s,
-                 util::Allocator* a,
+                 util::Alloc* a,
                  vm::Zone* zone,
                  ArchitectureContext* ac)
     : s(s),
diff --git a/src/codegen/target/x86/context.h b/src/codegen/target/x86/context.h
index 9a1eb912b8..93a6f1cc5b 100644
--- a/src/codegen/target/x86/context.h
+++ b/src/codegen/target/x86/context.h
@@ -26,7 +26,7 @@
 
 namespace vm {
 class System;
-class Allocator;
+class Alloc;
 class Zone;
 }  // namespace vm
 
@@ -80,7 +80,7 @@ class ArchitectureContext {
 class Context {
  public:
   Context(vm::System* s,
-          util::Allocator* a,
+          util::Alloc* a,
           vm::Zone* zone,
           ArchitectureContext* ac);
 
diff --git a/src/lzma-decode.cpp b/src/lzma-decode.cpp
index a1af7ae9fc..0630eda03d 100644
--- a/src/lzma-decode.cpp
+++ b/src/lzma-decode.cpp
@@ -27,7 +27,7 @@ int32_t read4(const uint8_t* in)
 namespace vm {
 
 uint8_t* decodeLZMA(System* s,
-                    avian::util::Allocator* a,
+                    avian::util::AllocOnly* a,
                     uint8_t* in,
                     unsigned inSize,
                     unsigned* outSize)
diff --git a/src/lzma-encode.cpp b/src/lzma-encode.cpp
index 8dc26586a3..cfaf3f3512 100644
--- a/src/lzma-encode.cpp
+++ b/src/lzma-encode.cpp
@@ -25,7 +25,7 @@ SRes myProgress(void*, UInt64, UInt64)
 namespace vm {
 
 uint8_t* encodeLZMA(System* s,
-                    Allocator* a,
+                    AllocOnly* a,
                     uint8_t* in,
                     unsigned inSize,
                     unsigned* outSize)