diff --git a/libpkgconf/tuple.c b/libpkgconf/tuple.c
index 26dc5d5..8523709 100644
--- a/libpkgconf/tuple.c
+++ b/libpkgconf/tuple.c
@@ -139,7 +139,7 @@ pkgconf_tuple_find_delete(pkgconf_list_t *list, const char *key)
 static char *
 dequote(const char *value)
 {
-	char *buf = calloc(strlen(value) * 2, 1);
+	char *buf = calloc((strlen(value) + 1) * 2, 1);
 	char *bptr = buf;
 	const char *i;
 	char quote = 0;