diff --git a/src/binaryToObject/elf.cpp b/src/binaryToObject/elf.cpp
index 51c7d7c587..5235c8f0a7 100644
--- a/src/binaryToObject/elf.cpp
+++ b/src/binaryToObject/elf.cpp
@@ -166,7 +166,7 @@ public:
     ElfObjectWriter(PlatformInfo::Architecture arch):
       arch(arch) {}
 
-    void writeObject(const uint8_t* data, unsigned size, FILE* out,
+    void writeObject(const uint8_t* data, unsigned size, OutputStream* out,
                      const char* startName, const char* endName,
                      const char* sectionName, unsigned sectionFlags,
                      unsigned alignment, int machine, int encoding)
@@ -311,31 +311,30 @@ public:
       endSymbol.st_other = V1(STV_DEFAULT);
       endSymbol.st_shndx = V2(bodySectionNumber);
 
-      fwrite(&fileHeader, 1, sizeof(fileHeader), out);
-      fwrite(&nullSection, 1, sizeof(nullSection), out);
-      fwrite(&bodySection, 1, sizeof(bodySection), out);
-      fwrite(&sectionStringTableSection, 1, sizeof(sectionStringTableSection),
-             out);
-      fwrite(&stringTableSection, 1, sizeof(stringTableSection), out);
-      fwrite(&symbolTableSection, 1, sizeof(symbolTableSection), out);
+      out->writeChunk(&fileHeader, sizeof(fileHeader));
+      out->writeChunk(&nullSection, sizeof(nullSection));
+      out->writeChunk(&bodySection, sizeof(bodySection));
+      out->writeChunk(&sectionStringTableSection, sizeof(sectionStringTableSection));
+      out->writeChunk(&stringTableSection, sizeof(stringTableSection));
+      out->writeChunk(&symbolTableSection, sizeof(symbolTableSection));
 
-      fwrite(data, 1, size, out);
+      out->writeChunk(data, size);
 
-      fputc(0, out);
-      fwrite(sectionStringTableName, 1, sectionStringTableNameLength, out);
-      fwrite(stringTableName, 1, stringTableNameLength, out);
-      fwrite(symbolTableName, 1, symbolTableNameLength, out);
-      fwrite(sectionName, 1, sectionNameLength, out);
+      out->write(0);
+      out->writeChunk(sectionStringTableName, sectionStringTableNameLength);
+      out->writeChunk(stringTableName, stringTableNameLength);
+      out->writeChunk(symbolTableName, symbolTableNameLength);
+      out->writeChunk(sectionName, sectionNameLength);
 
-      fputc(0, out);
-      fwrite(startName, 1, startNameLength, out);
-      fwrite(endName, 1, endNameLength, out);
+      out->write(0);
+      out->writeChunk(startName, startNameLength);
+      out->writeChunk(endName, endNameLength);
 
-      fwrite(&startSymbol, 1, sizeof(startSymbol), out);
-      fwrite(&endSymbol, 1, sizeof(endSymbol), out);
+      out->writeChunk(&startSymbol, sizeof(startSymbol));
+      out->writeChunk(&endSymbol, sizeof(endSymbol));
     }
 
-    virtual bool write(uint8_t* data, size_t size, FILE* out,
+    virtual bool write(uint8_t* data, size_t size, OutputStream* out,
                        const char* startName, const char* endName,
                        unsigned alignment, unsigned accessFlags)
     {
diff --git a/src/binaryToObject/mach-o.cpp b/src/binaryToObject/mach-o.cpp
index 6aab90a0b1..e040569212 100644
--- a/src/binaryToObject/mach-o.cpp
+++ b/src/binaryToObject/mach-o.cpp
@@ -148,7 +148,7 @@ public:
     MachOObjectWriter(PlatformInfo::Architecture arch):
       arch(arch) {}
 
-    void writeObject(const uint8_t* data, unsigned size, FILE* out,
+    void writeObject(const uint8_t* data, unsigned size, OutputStream* out,
                 const char* startName, const char* endName,
                 const char* segmentName, const char* sectionName,
                 unsigned alignment, cpu_type_t cpuType, cpu_subtype_t cpuSubType)
@@ -242,22 +242,23 @@ public:
         }
       };
 
-      fwrite(&header, 1, sizeof(header), out);
-      fwrite(&segment, 1, sizeof(segment), out);
-      fwrite(&sect, 1, sizeof(sect), out);
-      fwrite(&symbolTable, 1, sizeof(symbolTable), out);
+      out->writeChunk(&header, sizeof(header));
+      out->writeChunk(&segment, sizeof(segment));
+      out->writeChunk(&sect, sizeof(sect));
+      out->writeChunk(&symbolTable, sizeof(symbolTable));
 
-      fwrite(data, 1, size, out);
-      for (unsigned i = 0; i < pad(size) - size; ++i) fputc(0, out);
+      out->writeChunk(data, size);
+      out->writeRepeat(0, pad(size) - size);
 
-      fwrite(&symbolList, 1, sizeof(symbolList), out);
+      out->writeChunk(&symbolList, sizeof(symbolList));
 
-      fputc(0, out);
-      fwrite(startName, 1, startNameLength, out);
-      fwrite(endName, 1, endNameLength, out);
+      out->write(0);
+
+      out->writeChunk(startName, startNameLength);
+      out->writeChunk(endName, endNameLength);
     }
 
-    virtual bool write(uint8_t* data, size_t size, FILE* out,
+    virtual bool write(uint8_t* data, size_t size, OutputStream* out,
                        const char* startName, const char* endName,
                        unsigned alignment, unsigned accessFlags)
     {
diff --git a/src/binaryToObject/main.cpp b/src/binaryToObject/main.cpp
index 6dcdf9734d..197bcbf0f6 100644
--- a/src/binaryToObject/main.cpp
+++ b/src/binaryToObject/main.cpp
@@ -44,7 +44,7 @@ namespace {
 using namespace avian::tools;
 
 bool
-writeObject(uint8_t* data, unsigned size, FILE* out, const char* startName,
+writeObject(uint8_t* data, unsigned size, OutputStream* out, const char* startName,
             const char* endName, const char* os,
             const char* architecture, unsigned alignment, bool writable,
             bool executable)
@@ -142,13 +142,11 @@ main(int argc, const char** argv)
   bool success = false;
 
   if (data) {
-    FILE* out = fopen(argv[2], "wb");
-    if (out) {
+    FileOutputStream out(argv[2]);
+    if (out.isValid()) {
       success = writeObject
-        (data, size, out, argv[3], argv[4], argv[5], argv[6], alignment,
+        (data, size, &out, argv[3], argv[4], argv[5], argv[6], alignment,
          writable, executable);
-
-      fclose(out);
     } else {
       fprintf(stderr, "unable to open %s\n", argv[2]);
     }
diff --git a/src/binaryToObject/pe.cpp b/src/binaryToObject/pe.cpp
index 67fe684153..9fcdbe8949 100644
--- a/src/binaryToObject/pe.cpp
+++ b/src/binaryToObject/pe.cpp
@@ -79,8 +79,10 @@ pad(unsigned n)
   return (n + (4 - 1)) & ~(4 - 1);
 }
 
+using namespace avian::tools;
+
 void
-writeObject(const uint8_t* data, unsigned size, FILE* out,
+writeObject(const uint8_t* data, unsigned size, OutputStream* out,
             const char* startName, const char* endName,
             const char* sectionName, int machine, int machineMask,
             int sectionMask)
@@ -147,24 +149,22 @@ writeObject(const uint8_t* data, unsigned size, FILE* out,
   };
   endSymbol.N.Name.Long = endNameOffset;
 
-  fwrite(&fileHeader, 1, sizeof(fileHeader), out);
-  fwrite(&sectionHeader, 1, sizeof(sectionHeader), out);
+  out->writeChunk(&fileHeader, sizeof(fileHeader));
+  out->writeChunk(&sectionHeader, sizeof(sectionHeader));
 
-  fwrite(data, 1, size, out);
-  for (unsigned i = 0; i < pad(size) - size; ++i) fputc(0, out);
+  out->writeChunk(data, size);
+  out->writeRepeat(0, pad(size) - size);
 
-  fwrite(&startSymbol, 1, sizeof(startSymbol), out);
-  fwrite(&endSymbol, 1, sizeof(endSymbol), out);
+  out->writeChunk(&startSymbol, sizeof(startSymbol));
+  out->writeChunk(&endSymbol, sizeof(endSymbol));
 
   uint32_t symbolTableSize = endNameOffset + endNameLength;
-  fwrite(&symbolTableSize, 1, 4, out);
+  out->writeChunk(&symbolTableSize, 4);
 
-  fwrite(startName, 1, startNameLength, out);
-  fwrite(endName, 1, endNameLength, out);
+  out->writeChunk(startName, startNameLength);
+  out->writeChunk(endName, endNameLength);
 }
 
-using namespace avian::tools;
-
 template<unsigned BytesPerWord>
 class WindowsPlatform : public Platform {
 public:
@@ -172,7 +172,7 @@ public:
   class PEObjectWriter : public ObjectWriter {
   public:
 
-    virtual bool write(uint8_t* data, size_t size, FILE* out,
+    virtual bool write(uint8_t* data, size_t size, OutputStream* out,
                        const char* startName, const char* endName,
                        unsigned alignment, unsigned accessFlags)
     {
diff --git a/src/binaryToObject/tools.cpp b/src/binaryToObject/tools.cpp
index 531fd2f246..0768e8a24b 100644
--- a/src/binaryToObject/tools.cpp
+++ b/src/binaryToObject/tools.cpp
@@ -19,6 +19,37 @@ namespace avian {
 
 namespace tools {
 
+void OutputStream::write(uint8_t byte) {
+  writeChunk(&byte, 1);
+}
+
+void OutputStream::writeRepeat(uint8_t byte, size_t size) {
+  for(size_t i = 0; i < size; i++) {
+    write(byte);
+  }
+}
+
+FileOutputStream::FileOutputStream(const char* name):
+  file(fopen(name, "wb")) {}
+
+FileOutputStream::~FileOutputStream() {
+  if(file) {
+    fclose(file);
+  }
+}
+
+bool FileOutputStream::isValid() {
+  return file;
+}
+
+void FileOutputStream::writeChunk(const void* data, size_t size) {
+  fwrite(data, size, 1, file);
+}
+
+void FileOutputStream::write(uint8_t byte) {
+  fputc(byte, file);
+}
+
 
 Platform* Platform::first = 0;
 
diff --git a/src/binaryToObject/tools.h b/src/binaryToObject/tools.h
index 1d1b2d2a34..359068fe4d 100644
--- a/src/binaryToObject/tools.h
+++ b/src/binaryToObject/tools.h
@@ -15,6 +15,26 @@ namespace avian {
 
 namespace tools {
 
+class OutputStream {
+public:
+  virtual void writeChunk(const void* data, size_t size) = 0;
+  virtual void write(uint8_t byte);
+  virtual void writeRepeat(uint8_t byte, size_t size);
+};
+
+class FileOutputStream : public OutputStream {
+private:
+  FILE* file;
+public:
+  FileOutputStream(const char* name);
+  ~FileOutputStream();
+
+  bool isValid();
+
+  virtual void writeChunk(const void* data, size_t size);
+  virtual void write(uint8_t byte);
+};
+
 class ObjectWriter {
 public:
 
@@ -24,7 +44,7 @@ public:
     Executable = 1 << 2
   };
 
-  virtual bool write(uint8_t* data, size_t size, FILE* out,
+  virtual bool write(uint8_t* data, size_t size, OutputStream* out,
                      const char* startName, const char* endName,
                      unsigned alignment, unsigned accessFlags) = 0;