diff --git a/src/lib/libast/regex/regcomp.c b/src/lib/libast/regex/regcomp.c
index 060b5ea8..acb88be7 100644
--- a/src/lib/libast/regex/regcomp.c
+++ b/src/lib/libast/regex/regcomp.c
@@ -3278,7 +3278,7 @@ regcomp(regex_t* p, const char* pattern, regflags_t flags)
 	if (!(p->env = (Env_t*)alloc(disc, 0, sizeof(Env_t))))
 		return fatal(disc, REG_ESPACE, pattern);
 	memset(p->env, 0, sizeof(*p->env));
-	if (!(p->env->mst = stkopen(STK_SMALL|STK_NULL)))
+	if (!(p->env->mst = stkopen(STK_NULL)))
 		return fatal(disc, REG_ESPACE, pattern);
 	memset(&env, 0, sizeof(env));
 	env.regex = p;