diff --git a/config/powerpc-ibm-aix4.x b/config/powerpc-ibm-aix4.x
index eb93a7168e..1fe78e4749 100644
--- a/config/powerpc-ibm-aix4.x
+++ b/config/powerpc-ibm-aix4.x
@@ -120,3 +120,4 @@ fi
 
 # Use AIX supplied C++ compiler by default.
 CXX=${CXX=xlC}
+hdf5_mpi_complex_derived_datatype_works=${hdf5_mpi_complex_derived_datatype_works='no'}
diff --git a/config/powerpc-ibm-aix5.x b/config/powerpc-ibm-aix5.x
index 9ff4f4ecd6..924a4ea0ee 100644
--- a/config/powerpc-ibm-aix5.x
+++ b/config/powerpc-ibm-aix5.x
@@ -149,3 +149,10 @@ fi
 
 # Use AIX supplied C++ compiler by default.
 CXX=${CXX=xlC}
+# IBM MPI-IO implementation has a bug, 
+#it cannot generate correct MPI derived datatype.
+hdf5_mpi_complex_derived_datatype_works=${hdf5_mpi_complex_derived_datatype_works='no'}
+
+
+
+
diff --git a/config/rs6000-ibm-aix4.x b/config/rs6000-ibm-aix4.x
index 985a8c5dbf..928ad36787 100644
--- a/config/rs6000-ibm-aix4.x
+++ b/config/rs6000-ibm-aix4.x
@@ -42,3 +42,5 @@ if test "X-" = "X-$f9x_flags_set"; then
   PROFILE_FCFLAGS="-O"
   f9x_flags_set=yes
 fi
+# IBM MPI-IO doesn't handle complicated derived data type correctly.
+hdf5_mpi_complex_derived_datatype_works=${hdf5_mpi_complex_derived_datatype_works='no'}