diff --git a/src/share/vm/prims/jvmtiEnvBase.cpp b/src/share/vm/prims/jvmtiEnvBase.cpp
index 99f7514265201fb5c1087a84f7af65497e847134..c0c98f01e53c3b06eac8eecee67ba7fb9ba18289 100644
--- a/src/share/vm/prims/jvmtiEnvBase.cpp
+++ b/src/share/vm/prims/jvmtiEnvBase.cpp
@@ -94,6 +94,35 @@ JvmtiEnvBase::initialize() {
 }
 
 
+bool
+JvmtiEnvBase::is_valid() {
+  jint value = 0;
+
+  // This object might not be a JvmtiEnvBase so we can't assume
+  // the _magic field is properly aligned. Get the value in a safe
+  // way and then check against JVMTI_MAGIC.
+
+  switch (sizeof(_magic)) {
+  case 2:
+    value = Bytes::get_native_u2((address)&_magic);
+    break;
+
+  case 4:
+    value = Bytes::get_native_u4((address)&_magic);
+    break;
+
+  case 8:
+    value = Bytes::get_native_u8((address)&_magic);
+    break;
+
+  default:
+    guarantee(false, "_magic field is an unexpected size");
+  }
+
+  return value == JVMTI_MAGIC;
+}
+
+
 JvmtiEnvBase::JvmtiEnvBase() : _env_event_enable() {
   _env_local_storage = NULL;
   _tag_map = NULL;
diff --git a/src/share/vm/prims/jvmtiEnvBase.hpp b/src/share/vm/prims/jvmtiEnvBase.hpp
index 477725ffec5cd2c172bd61ac9099ce0382071a98..e6dd31e5870c7d22768c9d9784dc47006557ac8d 100644
--- a/src/share/vm/prims/jvmtiEnvBase.hpp
+++ b/src/share/vm/prims/jvmtiEnvBase.hpp
@@ -120,7 +120,7 @@ class JvmtiEnvBase : public CHeapObj {
 
  public:
 
-  bool is_valid()                                  { return _magic == JVMTI_MAGIC; }
+  bool is_valid();
 
   bool is_retransformable()                        { return _is_retransformable; }
 
diff --git a/src/share/vm/prims/jvmtiImpl.cpp b/src/share/vm/prims/jvmtiImpl.cpp
index f9a512c4222b8b579e5b351a27a9afb3bc3288a1..5a174b35bc3e53b712e7cde40231a6108fc9b8c7 100644
--- a/src/share/vm/prims/jvmtiImpl.cpp
+++ b/src/share/vm/prims/jvmtiImpl.cpp
@@ -238,6 +238,35 @@ JvmtiRawMonitor::~JvmtiRawMonitor() {
 }
 
 
+bool
+JvmtiRawMonitor::is_valid() {
+  int value = 0;
+
+  // This object might not be a JvmtiRawMonitor so we can't assume
+  // the _magic field is properly aligned. Get the value in a safe
+  // way and then check against JVMTI_RM_MAGIC.
+
+  switch (sizeof(_magic)) {
+  case 2:
+    value = Bytes::get_native_u2((address)&_magic);
+    break;
+
+  case 4:
+    value = Bytes::get_native_u4((address)&_magic);
+    break;
+
+  case 8:
+    value = Bytes::get_native_u8((address)&_magic);
+    break;
+
+  default:
+    guarantee(false, "_magic field is an unexpected size");
+  }
+
+  return value == JVMTI_RM_MAGIC;
+}
+
+
 //
 // class JvmtiBreakpoint
 //
diff --git a/src/share/vm/prims/jvmtiImpl.hpp b/src/share/vm/prims/jvmtiImpl.hpp
index d1b8414e61efa6c0cb84364ffda0265c88138899..2605546c62d047574b646b6bebd22a99b6d8e4e3 100644
--- a/src/share/vm/prims/jvmtiImpl.hpp
+++ b/src/share/vm/prims/jvmtiImpl.hpp
@@ -349,7 +349,7 @@ public:
   ~JvmtiRawMonitor();
   int            magic()   { return _magic;  }
   const char *get_name()   { return _name; }
-  bool        is_valid()   { return _magic == JVMTI_RM_MAGIC;  }
+  bool        is_valid();
 };
 
 // Onload pending raw monitors