diff --git a/src/Makefile.inc.in b/src/Makefile.inc.in
index 411422d..b5f1662 100644
--- a/src/Makefile.inc.in
+++ b/src/Makefile.inc.in
@@ -65,7 +65,7 @@ LANGUAGES = @LANGUAGES@
 docsdir = ${prefix}/share/doc/linuxcnc
 sampleconfsdir = ${prefix}/share/doc/linuxcnc/examples/sample-configs
 ncfilesdir = ${prefix}/share/linuxcnc/ncfiles
-tcldir = ${prefix}/lib/tcltk/linuxcnc
+tcldir = ${libdir}/tcl/linuxcnc
 
 
 # /Standard configure directories
diff --git a/src/configure.ac b/src/configure.ac
index 942e35b..38eb8b5 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -705,8 +705,8 @@ else
     EMC2_SCRIPT=$EMC2_BIN_DIR/linuxcnc
     EMC2_SUFFIX=""
     EMC2_ICON=linuxcncicon
-    EMC2_TCL_DIR=${prefix}/lib/tcltk/linuxcnc
-    EMC2_TCL_LIB_DIR=${prefix}/lib/tcltk/linuxcnc
+    EMC2_TCL_DIR=${libdir}/tcl/linuxcnc
+    EMC2_TCL_LIB_DIR=${libdir}/tcl/linuxcnc
     EMC2_LANG_DIR=${prefix}/lib/tcltk/linuxcnc/msgs
     EMC2_PO_DIR=${prefix}/share/locale
     EMC2_HELP_DIR=${prefix}/share/doc/linuxcnc
@@ -928,7 +928,7 @@ then
     AC_MSG_ERROR([fuser not found])
 fi
 
-AC_PATH_PROGS(YAPPS, yapps yapps2, "none", $SPATH)
+AC_PATH_PROGS(YAPPS, yapps yapps2 yapps2.py3, "none", $SPATH)
 if test $YAPPS = "none"
 then
     AC_MSG_ERROR([yapps/yapps2 and not found])
@@ -1609,7 +1609,7 @@ fi
 AC_MSG_RESULT([$PYTHON_TK_VERSION])
 
 AC_MSG_CHECKING(for site-package location)
-SITEPY=`$PYTHON -c 'import distutils.sysconfig; print(distutils.sysconfig.get_python_lib())'`
+SITEPY=`$PYTHON -c 'import distutils.sysconfig; print(distutils.sysconfig.get_python_lib(plat_specific=1))'`
 AC_MSG_RESULT($SITEPY)
 
 AC_MSG_CHECKING(for working GLU quadrics)