diff --git a/src/parsers/permutation.c b/src/parsers/permutation.c
index b16758413eeafe2ce2ae91db2ebbe7593681d3cd..ec256c4af1f76292847102d0a07eca5cb19e5bae 100644
--- a/src/parsers/permutation.c
+++ b/src/parsers/permutation.c
@@ -176,5 +176,6 @@ HParser* h_permutation__ma(HAllocator* mm__, void *args[]) {
   ret->vtable = &permutation_vt; 
   ret->env = (void*)s;
   ret->backend = PB_MIN;
+  ret->desugared = NULL;
   return ret;
 }
diff --git a/src/parsers/sequence.c b/src/parsers/sequence.c
index 55c0c8885573ef7779714efd49eaf64cc59ac878..5ca034ad50c1b752ff48e202008b21c0d1e75375 100644
--- a/src/parsers/sequence.c
+++ b/src/parsers/sequence.c
@@ -171,5 +171,6 @@ HParser* h_sequence__ma(HAllocator* mm__, void *args[]) {
   ret->vtable = &sequence_vt; 
   ret->env = (void*)s; 
   ret->backend = PB_MIN;
+  ret->desugared = NULL;
   return ret;
 }
diff --git a/src/t_regression.c b/src/t_regression.c
index 60ba86383776c5688de60010bec6186cd31e403c..4e8ad0cdfc9df5c8ba2df32e4faaead50218ee7a 100644
--- a/src/t_regression.c
+++ b/src/t_regression.c
@@ -259,7 +259,14 @@ static void test_bug_19() {
     // it, leading to a crash immediately afterwards in collect_nts.
     // We don't actually care if the compile succeeds or fails, just
     // that it doesn't crash.
-    int compile_result = h_compile(parser, PB_GLR, NULL);
+    h_compile(parser, PB_GLR, NULL);
+
+    // The same bug happened in h_sequence__ma.
+    h_compile(h_sequence__ma(&deadbeefing_allocator, args), PB_GLR, NULL);
+
+    // It also exists in h_permutation__ma, but it doesn't happen to
+    // manifest in the same way.  I don't know how to write a test for
+    // the h_permutation__ma case.
     g_assert_true(1);
 }