diff --git a/src/Makefile.in b/src/Makefile.in
index b7db98f5b..79a3e702a 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -47,7 +47,7 @@ export OBJCACHE_JOBS := -j $(shell objcache --jobs "$(OBJCACHE_HOSTS)")
 export OBJCACHE := @objcache --read --write
 endif
 
-UNDER_GIT = $(wildcard ../.git)
+UNDER_GIT = $(wildcard ../.git/logs/HEAD)
 
 #*********************************************************************
 
@@ -79,7 +79,7 @@ prefiles::
 ifneq ($(UNDER_GIT),)	# If local git tree... Else don't burden users
 prefiles:: config_rev.h
 # This output goes into srcdir, as we need to distribute it as part of the kit.
-config_rev.h:	config_rev.pl ../.git/index
+config_rev.h:	config_rev.pl ../.git/logs/HEAD
 	$(PERL) config_rev.pl . >$@
 endif