diff --git a/gitweb/Makefile b/gitweb/Makefile
index e32ee76309..0a6ac00631 100644
--- a/gitweb/Makefile
+++ b/gitweb/Makefile
@@ -40,6 +40,7 @@ HIGHLIGHT_BIN = highlight
 # include user config
 -include ../config.mak.autogen
 -include ../config.mak
+-include config.mak
 
 # determine version
 ../GIT-VERSION-FILE: .FORCE-GIT-VERSION-FILE
@@ -145,6 +146,15 @@ gitweb.cgi: gitweb.perl GITWEB-BUILD-OPTIONS
 	chmod +x $@+ && \
 	mv $@+ $@
 
+### Testing rules
+
+test:
+	$(MAKE) -C ../t gitweb-test
+
+test-installed:
+	GITWEB_TEST_INSTALLED='$(DESTDIR_SQ)$(gitwebdir_SQ)' \
+		$(MAKE) -C ../t gitweb-test
+
 ### Installation rules
 
 install: all
@@ -158,5 +168,5 @@ install: all
 clean:
 	$(RM) gitweb.cgi static/gitweb.min.js static/gitweb.min.css GITWEB-BUILD-OPTIONS
 
-.PHONY: all clean install .FORCE-GIT-VERSION-FILE FORCE
+.PHONY: all clean install test test-installed .FORCE-GIT-VERSION-FILE FORCE
 
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 253f41adc9..679f2da3ee 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -1075,6 +1075,7 @@ sub run_request {
 
 	evaluate_uri();
 	evaluate_gitweb_config();
+	evaluate_git_version();
 	check_loadavg();
 
 	# $projectroot and $projects_list might be set in gitweb config file
@@ -1127,7 +1128,6 @@ sub evaluate_argv {
 
 sub run {
 	evaluate_argv();
-	evaluate_git_version();
 
 	$pre_listen_hook->()
 		if $pre_listen_hook;
diff --git a/t/Makefile b/t/Makefile
index c7baefb7ea..7aa409ab64 100644
--- a/t/Makefile
+++ b/t/Makefile
@@ -17,6 +17,7 @@ SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 
 T = $(wildcard t[0-9][0-9][0-9][0-9]-*.sh)
 TSVN = $(wildcard t91[0-9][0-9]-*.sh)
+TGITWEB = $(wildcard t95[0-9][0-9]-*.sh)
 
 all: pre-clean
 	$(MAKE) aggregate-results-and-cleanup
@@ -46,6 +47,9 @@ full-svn-test:
 	$(MAKE) $(TSVN) GIT_SVN_NO_OPTIMIZE_COMMITS=1 LC_ALL=C
 	$(MAKE) $(TSVN) GIT_SVN_NO_OPTIMIZE_COMMITS=0 LC_ALL=en_US.UTF-8
 
+gitweb-test:
+	$(MAKE) $(TGITWEB)
+
 valgrind:
 	GIT_TEST_OPTS=--valgrind $(MAKE)
 
diff --git a/t/gitweb-lib.sh b/t/gitweb-lib.sh
index 8c490c8707..8b5b987f45 100644
--- a/t/gitweb-lib.sh
+++ b/t/gitweb-lib.sh
@@ -32,17 +32,34 @@ EOF
 	cat >.git/description <<EOF
 $0 test repository
 EOF
+
+	# You can set the GITWEB_TEST_INSTALLED environment variable to
+	# the gitwebdir (the directory where gitweb is installed / deployed to)
+	# of an existing gitweb instalation to test that installation,
+	# or simply to pathname of installed gitweb script.
+	if test -n "$GITWEB_TEST_INSTALLED" ; then
+		if test -d $GITWEB_TEST_INSTALLED; then
+			SCRIPT_NAME="$GITWEB_TEST_INSTALLED/gitweb.cgi"
+		else
+			SCRIPT_NAME="$GITWEB_TEST_INSTALLED"
+		fi
+		test -f "$SCRIPT_NAME" ||
+		error "Cannot find gitweb at $GITWEB_TEST_INSTALLED."
+		say "# Testing $SCRIPT_NAME"
+	else # normal case, use source version of gitweb
+		SCRIPT_NAME="$GIT_BUILD_DIR/gitweb/gitweb.perl"
+	fi
+	export SCRIPT_NAME
 }
 
 gitweb_run () {
 	GATEWAY_INTERFACE='CGI/1.1'
 	HTTP_ACCEPT='*/*'
 	REQUEST_METHOD='GET'
-	SCRIPT_NAME="$GIT_BUILD_DIR/gitweb/gitweb.perl"
 	QUERY_STRING=""$1""
 	PATH_INFO=""$2""
 	export GATEWAY_INTERFACE HTTP_ACCEPT REQUEST_METHOD \
-		SCRIPT_NAME QUERY_STRING PATH_INFO
+		QUERY_STRING PATH_INFO
 
 	GITWEB_CONFIG=$(pwd)/gitweb_config.perl
 	export GITWEB_CONFIG