diff --git a/src/spicelib/devices/adms/admst/ngspiceMakefile.am.xml b/src/spicelib/devices/adms/admst/ngspiceMakefile.am.xml
index 6a47f4904..249a25862 100644
--- a/src/spicelib/devices/adms/admst/ngspiceMakefile.am.xml
+++ b/src/spicelib/devices/adms/admst/ngspiceMakefile.am.xml
@@ -3,7 +3,10 @@
 <!--
   $Id$
   $Log$
-  Revision 1.3  2006-02-08 09:28:11  pnenzi
+  Revision 1.4  2006-02-16 09:17:40  dwarning
+  Add .bak to perl -i switch because some interpreter versions struggles about
+
+  Revision 1.3  2006/02/08 09:28:11  pnenzi
 
   Changed admsXml.exe to admsXml
   +8
@@ -67,7 +70,7 @@ adms:
 	-e \$(ADMSXMLINTERFACE)/ngspiceMODULEsetup.c.xml \\
 	-e \$(ADMSXMLINTERFACE)/ngspiceMODULEguesstopology.c.xml \\
 	-e \$(ADMSXMLINTERFACE)/ngspiceMODULE.c.xml
-	perl -p -i -e 's/IOP\\("(\\w+)"/IOP("\\L\\1"/' $(module).c
+	perl -p -i.bak -e 's/IOP\\("(\\w+)"/IOP("\\L\\1"/' $(module).c
 
 noinst_LIBRARIES = lib$(module).a