diff --git a/src/monitor.cc b/src/monitor.cc
index b641160..662e199 100644
--- a/src/monitor.cc
+++ b/src/monitor.cc
@@ -194,7 +194,7 @@
   if (!lock_.TryLock()) {
     uint32_t wait_threshold = lock_profiling_threshold_;
     const Method* current_locking_method = NULL;
-    uint32_t current_locking_pc = 0;
+    uintptr_t current_locking_pc = 0;
     {
       ScopedThreadStateChange tsc(self, Thread::kBlocked);
       if (wait_threshold != 0) {
@@ -368,7 +368,7 @@
   owner_ = NULL;
   const Method* savedMethod = locking_method_;
   locking_method_ = NULL;
-  uint32_t savedPc = locking_pc_;
+  uintptr_t savedPc = locking_pc_;
   locking_pc_ = 0;
 
   /*
diff --git a/src/monitor.h b/src/monitor.h
index 0a8c795..4d73e37 100644
--- a/src/monitor.h
+++ b/src/monitor.h
@@ -122,7 +122,7 @@
   // sampling is enabled. locking_method_ may be null if the lock is currently
   // unlocked, or if the lock is acquired by the system when the stack is empty.
   const Method* locking_method_;
-  uint32_t locking_pc_;
+  uintptr_t locking_pc_;
 
   friend class MonitorList;
   friend class Object;
diff --git a/src/mutex.cc b/src/mutex.cc
index 7507566..666c368 100644
--- a/src/mutex.cc
+++ b/src/mutex.cc
@@ -95,7 +95,6 @@
   reinterpret_cast<glibc_pthread_t*>(&mutex_)->owner = 0;
 #else
   UNIMPLEMENTED(FATAL);
-  return 0;
 #endif
 }