diff --git a/lib/construct.c b/lib/construct.c
index f0b2417..8ff33fc 100644
--- a/lib/construct.c
+++ b/lib/construct.c
@@ -128,19 +128,6 @@ static void construct_symbol(fsa_t *out, int symbol)
 	fsa_add_rule(out, out->initial, 0, symbol);
 }
 
-static void construct_star(fsa_t *out)
-{
-	fsa_t f;
-	memcpy(&f, out, sizeof(fsa_t));
-
-	construct_symbol(out, EPSILON);
-	int f_initial, f_final;
-	add_fsa(out, &f, &f_initial, &f_final);
-	fsa_add_rule(out, out->initial, f_initial, EPSILON);
-	fsa_add_rule(out, f_final, f_initial, EPSILON);
-	fsa_add_rule(out, f_final, 0, EPSILON);
-}
-
 static bool in_class(const regex_class_t *class, char c)
 {
 	for (int i = 0; i < class->count; ++i) {
@@ -171,6 +158,38 @@ static void construct_wildcard(fsa_t *out)
 		fsa_add_rule(out, out->initial, 0, i);
 }
 
+static void base_quantify(fsa_t *out, int *init_out, int *final_out)
+{
+	fsa_t f;
+	memcpy(&f, out, sizeof(fsa_t));
+	construct_base(out);
+	add_fsa(out, &f, init_out, final_out);
+	fsa_add_rule(out, out->initial, *init_out, EPSILON);
+	fsa_add_rule(out, *final_out, 0, EPSILON);
+}
+
+static void construct_star(fsa_t *out)
+{
+	int sub_init, sub_final;
+	base_quantify(out, &sub_init, &sub_final);
+	fsa_add_rule(out, sub_final, sub_init, EPSILON);
+	fsa_add_rule(out, out->initial, 0, EPSILON);
+}
+
+static void construct_plus(fsa_t *out)
+{
+	int sub_init, sub_final;
+	base_quantify(out, &sub_init, &sub_final);
+	fsa_add_rule(out, sub_final, sub_init, EPSILON);
+}
+
+static void construct_qmark(fsa_t *out)
+{
+	int sub_init, sub_final;
+	base_quantify(out, &sub_init, &sub_final);
+	fsa_add_rule(out, out->initial, 0, EPSILON);
+}
+
 static void construct_term(const regex_term_t *term, fsa_t *out)
 {
 	switch (term->type) {
@@ -198,8 +217,10 @@ static void construct_term(const regex_term_t *term, fsa_t *out)
 		construct_star(out);
 		break;
 	case REGEX_QUANTIFIER_PLUS:
+		construct_plus(out);
+		break;
 	case REGEX_QUANTIFIER_QMARK:
-		assert(false);
+		construct_qmark(out);
 		break;
 	}
 
diff --git a/tests/construct_tests.c b/tests/construct_tests.c
index 155330d..e5763c6 100644
--- a/tests/construct_tests.c
+++ b/tests/construct_tests.c
@@ -181,6 +181,52 @@ static void test_star(void)
 	fsa_free(&fsa);
 }
 
+static void test_plus(void)
+{
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_PLUS;
+	terms[0].type = REGEX_TERM_LITERAL;
+	terms[0].literal = 'a';
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t regex = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	fsa_t fsa;
+	construct_nfa(&regex, &fsa);
+
+	ASSERT_TRUE(accepts(&fsa, "a"));
+	ASSERT_TRUE(accepts(&fsa, "aaaaaa"));
+	ASSERT_FALSE(accepts(&fsa, ""));
+	ASSERT_FALSE(accepts(&fsa, "b"));
+
+	regex_free(&regex);
+	fsa_free(&fsa);
+}
+
+static void test_qmark(void)
+{
+	regex_term_t *terms = malloc(1 * sizeof(regex_term_t));
+	terms[0].quantifier = REGEX_QUANTIFIER_QMARK;
+	terms[0].type = REGEX_TERM_LITERAL;
+	terms[0].literal = 'a';
+	regex_sequence_t *alternatives = malloc(1 * sizeof(regex_sequence_t));
+	alternatives[0].count = alternatives[0].capacity = 1;
+	alternatives[0].contents = terms;
+	regex_t regex = { .count = 1, .capacity = 1, .contents = alternatives };
+
+	fsa_t fsa;
+	construct_nfa(&regex, &fsa);
+
+	ASSERT_TRUE(accepts(&fsa, ""));
+	ASSERT_TRUE(accepts(&fsa, "a"));
+	ASSERT_FALSE(accepts(&fsa, "aa"));
+	ASSERT_FALSE(accepts(&fsa, "b"));
+
+	regex_free(&regex);
+	fsa_free(&fsa);
+}
+
 static void test_subexpression(void)
 {
 	regex_term_t *inner_terms = malloc(1 * sizeof(regex_term_t));
@@ -415,6 +461,8 @@ int main(void)
 	test_sequence();
 	test_union();
 	test_star();
+	test_plus();
+	test_qmark();
 	test_subexpression();
 	test_class();
 	test_negated_class();