diff --git a/tests/alignment_test.cpp b/tests/alignment_test.cpp
index b7c2a6f..e91855b 100644
--- a/tests/alignment_test.cpp
+++ b/tests/alignment_test.cpp
@@ -40,5 +40,10 @@ int main(int argc, char* argv[])
 
 //
 // define the number of failures expected for given compilers:
+#ifdef __MWERKS__
+unsigned int expected_failures = 5;
+#else
 unsigned int expected_failures = 0;
+#endif
+
 
diff --git a/tests/composite_traits_test.cpp b/tests/composite_traits_test.cpp
index e6e564a..0ceed2f 100644
--- a/tests/composite_traits_test.cpp
+++ b/tests/composite_traits_test.cpp
@@ -109,8 +109,11 @@ unsigned int expected_failures = 2;
 unsigned int expected_failures = 1; // can't handle cv-qualified references
 #elif defined(BOOST_MSVC)
 unsigned int expected_failures = 1;
+#elif defined(__MWERKS__)
+unsigned int expected_failures = 1; // is_enum doesn't work
 #else
 unsigned int expected_failures = 0;
 #endif
 
 
+
diff --git a/tests/object_type_traits_test.cpp b/tests/object_type_traits_test.cpp
index edb9edf..18200f4 100644
--- a/tests/object_type_traits_test.cpp
+++ b/tests/object_type_traits_test.cpp
@@ -166,7 +166,12 @@ int main(int argc, char* argv[])
    // because we can't tell the difference between
    // unions and classes:
    value_fail(true, boost::is_empty<empty_union_UDT>::value)
+#if defined(__MWERKS__)
+   // apparent compiler bug causes this to fail to compile:
+   value_fail(false, boost::is_empty<enum_UDT>::value)
+#else
    soft_value_test(false, boost::is_empty<enum_UDT>::value)
+#endif
    soft_value_test(true, boost::is_empty<boost::noncopyable>::value)
    soft_value_test(false, boost::is_empty<non_empty>::value)
 
@@ -189,3 +194,4 @@ unsigned int expected_failures = 4;
 #endif
 
 
+