diff --git a/format.c b/format.c
index d82d1805..ae3086d1 100644
--- a/format.c
+++ b/format.c
@@ -1256,6 +1256,7 @@ format_replace(struct format_tree *ft, const char *key, size_t keylen,
 
 	/* Make a copy of the key. */
 	copy = copy0 = xstrndup(key, keylen);
+	log_debug("%s: format = '%s'", __func__, copy);
 
 	/* Process modifier list. */
 	list = format_build_modifiers(ft, &copy, &count);
@@ -1322,7 +1323,6 @@ format_replace(struct format_tree *ft, const char *key, size_t keylen,
 				cmp = fm;
 		}
 	}
-	log_debug("%s: remaining = '%s'", __func__, copy);
 
 	/* Is this a literal string? */
 	if (modifiers & FORMAT_LITERAL) {
@@ -1452,6 +1452,7 @@ done:
 	}
 
 	/* Expand the buffer and copy in the value. */
+	log_debug("%s: '%s' -> '%s'", __func__, copy0, value);
 	valuelen = strlen(value);
 	while (*len - *off < valuelen + 1) {
 		*buf = xreallocarray(*buf, 2, *len);