diff --git a/src/ML-IAP/Install.sh b/src/ML-IAP/Install.sh
index 2f2fa50921..38e3b574c2 100755
--- a/src/ML-IAP/Install.sh
+++ b/src/ML-IAP/Install.sh
@@ -41,13 +41,16 @@ for file in *.cpp *.h; do
 done
 
 # Edit makefile for ace descriptors if ML-PACE is available
-if (test $1 = 1) then
+if (test $1 = 1 || test $1 = 2) then
   if (test -e ../Makefile.package) then
+    sed -i -e 's/[^ \t]*-DMLIAP_ACE[^ \t]* //g' ../Makefile.package
     if (test -e ../compute_pace.h) then
       sed -i -e 's|^PKG_INC =[ \t]*|&-DMLIAP_ACE |' ../Makefile.package
-    fi
     else
       rm -f ../mliap_descriptor_ace.cpp ../mliap_descriptor_ace.h
+    fi
+  else
+    rm -f ../mliap_descriptor_ace.cpp ../mliap_descriptor_ace.h
   fi
 fi
 
@@ -80,6 +83,10 @@ elif (test $1 = 0) then
   rm -f ../mliap_model_python_couple.cpp ../mliap_model_python_couple.h \
     ../mliap_unified_couple.cpp ../mliap_unified_couple.h
   sed -i -e '/^[ \t]*include.*python.*mliap_python.*$/d' ../Makefile.package.settings
+  if (test -e ../Makefile.package) then
+    sed -i -e 's/[^ \t]*-DMLIAP_ACE[^ \t]* //g' ../Makefile.package
+  fi
+  rm -f ../mliap_descriptor_ace.cpp ../mliap_descriptor_ace.h
 
 elif (test $1 = 2) then
   if (type cythonize > /dev/null 2>&1 && test -e ../python_impl.cpp) then