diff --git a/git-fmt-merge-msg.perl b/git-fmt-merge-msg.perl
index 1b23fa1..a9805dd 100755
--- a/git-fmt-merge-msg.perl
+++ b/git-fmt-merge-msg.perl
@@ -5,7 +5,11 @@
 # Read .git/FETCH_HEAD and make a human readable merge message
 # by grouping branches and tags together to form a single line.
 
-BEGIN { unshift @INC, '@@INSTLIBDIR@@'; }
+BEGIN {
+	unless (exists $ENV{'RUNNING_GIT_TESTS'}) {
+		unshift @INC, '@@INSTLIBDIR@@';
+	}
+}
 use strict;
 use Git;
 use Error qw(:try);
diff --git a/git-mv.perl b/git-mv.perl
index a604896..5134b80 100755
--- a/git-mv.perl
+++ b/git-mv.perl
@@ -6,7 +6,11 @@
 # This file is licensed under the GPL v2, or a later version
 # at the discretion of Linus Torvalds.
 
-BEGIN { unshift @INC, '@@INSTLIBDIR@@'; }
+BEGIN {
+	unless (exists $ENV{'RUNNING_GIT_TESTS'}) {
+		unshift @INC, '@@INSTLIBDIR@@';
+	}
+}
 use warnings;
 use strict;
 use Getopt::Std;
diff --git a/t/test-lib.sh b/t/test-lib.sh
index fba0c51..298c6ca 100755
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -206,8 +206,9 @@
 	PYTHONPATH=$(pwd)/../compat
 	export PYTHONPATH
 }
+RUNNING_GIT_TESTS=YesWeAre
 PERL5LIB=$(pwd)/../perl/blib/lib:$(pwd)/../perl/blib/arch/auto/Git
-export PERL5LIB
+export PERL5LIB RUNNING_GIT_TESTS
 test -d ../templates/blt || {
 	error "You haven't built things yet, have you?"
 }