diff --git a/auto/configure b/auto/configure
index 786f4f8..6a81555 100755
--- a/auto/configure
+++ b/auto/configure
@@ -46,7 +46,7 @@
 have=NGX_SBIN_PATH value="\"$SBIN_PATH\"" . auto/define
 have=NGX_CONF_PATH value="\"$CONF_PATH\"" . auto/define
 have=NGX_PID_PATH value="\"$PID_PATH\"" . auto/define
-if [ ".$NGX_ERROR_LOG_PATH" != "." ]; then
+if [ ".$ERROR_LOG_PATH" != "." ]; then
     have=NGX_ERROR_LOG_PATH value="\"$ERROR_LOG_PATH\"" . auto/define
 fi
 have=NGX_HTTP_LOG_PATH value="\"$HTTP_LOG_PATH\"" . auto/define
diff --git a/auto/install b/auto/install
index d1d608c..31a191d 100644
--- a/auto/install
+++ b/auto/install
@@ -52,6 +52,13 @@
 clean:
 	rm -rf Makefile $OBJS
 
+upgrade:
+	$SBIN_PATH -t
+	kill -USR2 \`cat $PID_PATH\`
+	sleep 1
+	test -f $PID_PATH.newbin
+	kill -WINCH \`cat $PID_PATH\`
+
 END
 
 fi
diff --git a/auto/modules b/auto/modules
index 7bb1eb9..6c5111a 100644
--- a/auto/modules
+++ b/auto/modules
@@ -118,7 +118,7 @@
 
 if [ $HTTP_PROXY = YES ]; then
     have=NGX_HTTP_PROXY . auto/have
-    USE_MD5=YES
+    #USE_MD5=YES
     HTTP_MODULES="$HTTP_MODULES $HTTP_PROXY_MODULE"
     HTTP_INCS="$HTTP_INCS $HTTP_PROXY_INCS"
     HTTP_DEPS="$HTTP_DEPS $HTTP_PROXY_DEPS"
diff --git a/auto/summary b/auto/summary
index a07c78c..45c68e0 100644
--- a/auto/summary
+++ b/auto/summary
@@ -43,12 +43,26 @@
 
 
 if [ $HTTP_REWRITE = YES ]; then
+    if [ $USE_PCRE = DISABLED ]; then
+
+cat << END
+$0: error: the HTTP rewrite module requires the PCRE library.
+You can either disable the module by using --without-http_rewrite_module
+option or you have to enable the PCRE support.
+
+END
+        exit 1
+    fi
+
     if [ $PCRE = NONE -o $PCRE = NO ]; then
-        echo "$0: error: HTTP rewrite module requires PCRE library."
-        echo $ngx_n "You can disable the module by using " $ngx_c
-        echo "--without-http_rewrite_module option"
-        echo "or you have to enable PCRE support."
-        echo
+
+cat << END
+$0: error: the HTTP rewrite module requires the PCRE library.
+You can either disable the module by using --without-http_rewrite_module
+option, or install the PCRE library into the system, or build the PCRE library
+statically from the source with nginx by using --with-pcre=<path> option.
+
+END
 
         exit 1
     fi
@@ -57,11 +71,14 @@
 
 if [ $HTTP_GZIP = YES ]; then
     if [ $ZLIB = NONE -o $ZLIB = NO ]; then
-        echo "$0: error: HTTP gzip module requires zlib library."
-        echo $ngx_n "You can disable the module by using " $ngx_c
-        echo "--without-http_gzip_module option"
-        echo "or you have to enable zlib support."
-        echo
+
+cat << END
+$0: error: the HTTP gzip module requires the zlib library.
+You can either disable the module by using --without-http_gzip_module
+option, or install the zlib library into the system, or build the zlib library
+statically from the source with nginx by using --with-zlib=<path> option.
+
+END
 
         exit 1
     fi