diff --git a/src/common/mac/macho_walker.cc b/src/common/mac/macho_walker.cc
index b2948b71..eee27d64 100644
--- a/src/common/mac/macho_walker.cc
+++ b/src/common/mac/macho_walker.cc
@@ -51,7 +51,7 @@ namespace MacFileUtilities {
 
 MachoWalker::MachoWalker(const char *path, LoadCommandCallback callback,
                          void *context)
-    : file_(0),
+    : file_(-1),
       memory_(NULL),
       memory_size_(0),
       callback_(callback),
@@ -64,7 +64,7 @@ MachoWalker::MachoWalker(const char *path, LoadCommandCallback callback,
 
 MachoWalker::MachoWalker(void *memory, size_t size,
                          LoadCommandCallback callback, void *context)
-    : file_(0),
+    : file_(-1),
       memory_(memory),
       memory_size_(size),
       callback_(callback),