diff --git a/config/RULES.Db b/config/RULES.Db
index 266dfab13..b630fa275 100644
--- a/config/RULES.Db
+++ b/config/RULES.Db
@@ -3,7 +3,13 @@
 #	Rules for making things related to databases
 #
 MAKEBPT		= $(EPICS_BASE_HOST_BIN)/makeBpt$(EXE)
-MSI		= $(EPICS_EXTENSIONS_BIN)/msi$(EXE)
+
+ifndef MSI
+# Tool from R3.14 extensions bin, R3.13 extensions bin, or user path
+MSI = $(firstword $(wildcard $(EPICS_EXTENSIONS_HOST_BIN)/msi$(HOSTEXE) \
+         $(EPICS_EXTENSIONS)/bin/$(HOST_OS_CLASS)/msi$(HOSTEXE)) msi$(HOSTEXE))
+endif
+
 DBEXPAND	= $(EPICS_BASE_HOST_BIN)/dbExpand$(EXE)
 DBST		= dbst
 MAKEDBDEPENDS	= $(PERL) $(TOP)/config/makeDbDepends.pl