--- a/config/ompi_fortran_check_real16_c_equiv.m4
+++ b/config/ompi_fortran_check_real16_c_equiv.m4
@@ -49,7 +49,6 @@
                              [AC_MSG_CHECKING([if intel compiler _Quad == REAL*16])
                               CFLAGS_save="$CFLAGS"
                               CFLAGS="$CFLAGS -Qoption,cpp,--extended_float_types"
-                              OPAL_FLAGS_UNIQ([CFLAGS])
                               OMPI_FORTRAN_CHECK_REAL16_EQUIV_TYPE([_Quad], [q])
                               AS_IF([test "$happy" = "yes"],
                                     [OMPI_FORTRAN_REAL16_C_TYPE="_Quad"
@@ -59,7 +58,6 @@
                              ])
                        AS_IF([test "$opal_cv_c_compiler_vendor" = "gnu" && test "$ac_cv_type___float128" = "yes"],
                              [AC_MSG_CHECKING([if gnu compiler __float128 == REAL*16])
-                              OPAL_FLAGS_UNIQ([CFLAGS])
                               OMPI_FORTRAN_CHECK_REAL16_EQUIV_TYPE([__float128], [q])
                               AS_IF([test "$happy" = "yes"],
                                     [OMPI_FORTRAN_REAL16_C_TYPE="__float128"
--- a/config/ompi_setup_cxx.m4
+++ b/config/ompi_setup_cxx.m4
@@ -162,7 +162,6 @@
     # Do we want debugging?
     if test "$WANT_DEBUG" = "1" && test "$enable_debug_symbols" != "no" ; then
         CXXFLAGS="$CXXFLAGS -g"
-        OPAL_FLAGS_UNIQ(CXXFLAGS)
         AC_MSG_WARN([-g has been added to CXXFLAGS (--enable-debug)])
     fi
 
@@ -204,7 +203,6 @@
         fi
 
         CXXFLAGS="$CXXFLAGS $add"
-        OPAL_FLAGS_UNIQ(CXXFLAGS)
         if test "$add" != "" ; then
             AC_MSG_WARN([$add has been added to CXXFLAGS (--enable-picky)])
         fi
@@ -227,7 +225,6 @@
             add=" -finline-functions"
         fi
         CXXFLAGS="$CXXFLAGS_orig$add"
-        OPAL_FLAGS_UNIQ(CXXFLAGS)
         if test "$add" != "" ; then
             AC_MSG_WARN([$add has been added to CXXFLAGS])
         fi
--- a/config/ompi_setup_fc.m4
+++ b/config/ompi_setup_fc.m4
@@ -68,7 +68,6 @@
 
     AS_IF([test $ompi_fc_happy -eq 1 && test "$WANT_DEBUG" = "1" && test "$enable_debug_symbols" != "no"],
           [FCFLAGS="$FCFLAGS -g"
-           OPAL_FLAGS_UNIQ(FCFLAGS)
            AC_MSG_WARN([-g has been added to FCFLAGS (--enable-debug)])
           ])
 
--- a/config/opal_setup_cc.m4
+++ b/config/opal_setup_cc.m4
@@ -105,7 +105,6 @@
             OPAL_WRAPPER_FLAGS_ADD([CFLAGS], [$OPAL_COVERAGE_FLAGS])
             OPAL_WRAPPER_FLAGS_ADD([LDFLAGS], [$OPAL_COVERAGE_FLAGS])
 
-            OPAL_FLAGS_UNIQ(CFLAGS)
             OPAL_FLAGS_UNIQ(LDFLAGS)
             AC_MSG_WARN([$OPAL_COVERAGE_FLAGS has been added to CFLAGS (--enable-coverage)])
 
@@ -120,7 +119,6 @@
     if test "$WANT_DEBUG" = "1" && test "$enable_debug_symbols" != "no" ; then
         CFLAGS="$CFLAGS -g"
 
-        OPAL_FLAGS_UNIQ(CFLAGS)
         AC_MSG_WARN([-g has been added to CFLAGS (--enable-debug)])
     fi
 
@@ -186,7 +184,6 @@
         fi
 
         CFLAGS="$CFLAGS_orig $add"
-        OPAL_FLAGS_UNIQ(CFLAGS)
         AC_MSG_WARN([$add has been added to CFLAGS (--enable-picky)])
         unset add
     fi
@@ -236,7 +233,6 @@
         fi
         CFLAGS="$CFLAGS_orig$add"
 
-        OPAL_FLAGS_UNIQ(CFLAGS)
         AC_MSG_WARN([$add has been added to CFLAGS])
         unset add
     fi
@@ -265,7 +261,6 @@
         fi
 
         CFLAGS="${CFLAGS_orig}${add}"
-        OPAL_FLAGS_UNIQ([CFLAGS])
         if test "$add" != "" ; then
             AC_MSG_WARN([$add has been added to CFLAGS])
         fi
--- a/config/opal_setup_cxx.m4
+++ b/config/opal_setup_cxx.m4
@@ -96,7 +96,6 @@
     # Do we want debugging?
     if test "$WANT_DEBUG" = "1" && test "$enable_debug_symbols" != "no" ; then
         CXXFLAGS="$CXXFLAGS -g"
-        OPAL_FLAGS_UNIQ(CXXFLAGS)
         AC_MSG_WARN([-g has been added to CXXFLAGS (--enable-debug)])
     fi
 
@@ -142,7 +141,6 @@
         fi
 
         CXXFLAGS="$CXXFLAGS $add"
-        OPAL_FLAGS_UNIQ(CXXFLAGS)
         if test "$add" != "" ; then
             AC_MSG_WARN([$add has been added to CXXFLAGS (--enable-picky)])
         fi
@@ -165,7 +163,6 @@
             add=" -finline-functions"
         fi
         CXXFLAGS="$CXXFLAGS_orig$add"
-        OPAL_FLAGS_UNIQ(CXXFLAGS)
         if test "$add" != "" ; then
             AC_MSG_WARN([$add has been added to CXXFLAGS])
         fi