diff --git a/doc/configuration.txt b/doc/configuration.txt
index ca4c581..be8cb9e 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -14642,12 +14642,12 @@
   seconds, which means that you can't cache an object more than 60 seconds by
   default.
 
-process-vary <0 or 1>
-  Disable or enable the processing of the Vary header. When disabled, a response
+process-vary <on/off>
+  Enable or disable the processing of the Vary header. When disabled, a response
   containing such a header will never be cached. When enabled, we need to calculate
   a preliminary hash for a subset of request headers on all the incoming requests
   (which might come with a cpu cost) which will be used to build a secondary key
-  for a given request (see RFC 7234#4.1). The default value is 0 (disabled).
+  for a given request (see RFC 7234#4.1). The default value is off (disabled).
 
 max-secondary-entries <number>
   Define the maximum number of simultaneous secondary entries with the same primary
diff --git a/reg-tests/cache/vary.vtc b/reg-tests/cache/vary.vtc
index 4e1958f..a840799 100644
--- a/reg-tests/cache/vary.vtc
+++ b/reg-tests/cache/vary.vtc
@@ -145,13 +145,13 @@
                total-max-size 3
                max-age 20
                max-object-size 3072
-               process-vary 1
+               process-vary on
 
        cache no_vary_cache
                total-max-size 3
                max-age 20
                max-object-size 3072
-               process-vary 0
+               process-vary off
 } -start
 
 
diff --git a/reg-tests/cache/vary_accept_encoding.vtc b/reg-tests/cache/vary_accept_encoding.vtc
index 9b55dc9..afd2cfb 100644
--- a/reg-tests/cache/vary_accept_encoding.vtc
+++ b/reg-tests/cache/vary_accept_encoding.vtc
@@ -98,7 +98,7 @@
                total-max-size 3
                max-age 20
                max-object-size 3072
-               process-vary 1
+               process-vary on
 } -start
 
 
diff --git a/src/cache.c b/src/cache.c
index 1f1428d..c740818 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -1981,12 +1981,19 @@
 		}
 
 		if (!*args[1]) {
-			ha_warning("parsing [%s:%d]: '%s' expects 0 or 1 (disable or enable vary processing).\n",
+			ha_warning("parsing [%s:%d]: '%s' expects \"on\" or \"off\" (enable or disable vary processing).\n",
 				   file, linenum, args[0]);
 			err_code |= ERR_WARN;
 		}
-
-		tmp_cache_config->vary_processing_enabled = atoi(args[1]);
+		if (strcmp(args[1], "on") == 0)
+			tmp_cache_config->vary_processing_enabled = 1;
+		else if (strcmp(args[1], "off") == 0)
+			tmp_cache_config->vary_processing_enabled = 0;
+		else {
+			ha_warning("parsing [%s:%d]: '%s' expects \"on\" or \"off\" (enable or disable vary processing).\n",
+				   file, linenum, args[0]);
+			err_code |= ERR_WARN;
+		}
 	} else if (strcmp(args[0], "max-secondary-entries") == 0) {
 		unsigned int max_sec_entries;
 		char *err;