diff --git a/contrib/prometheus-exporter/service-prometheus.c b/contrib/prometheus-exporter/service-prometheus.c
index 54f3732..b2cf9c8 100644
--- a/contrib/prometheus-exporter/service-prometheus.c
+++ b/contrib/prometheus-exporter/service-prometheus.c
@@ -2277,7 +2277,7 @@
 			*(p++) = 0;
 		else if (*p == '#')
 			*p = 0;
-		len = url_decode(key);
+		len = url_decode(key, 1);
 		if (len == -1)
 			goto error;
 
@@ -2291,7 +2291,7 @@
 				*(p++) = 0;
 			else if (*p == '#')
 				*p = 0;
-			len = url_decode(value);
+			len = url_decode(value, 1);
 			if (len == -1)
 				goto error;
 		}