diff --git a/qpms/scatsystem.h b/qpms/scatsystem.h
index c9a9a91..33ecc86 100644
--- a/qpms/scatsystem.h
+++ b/qpms/scatsystem.h
@@ -230,7 +230,7 @@ complex double *qpms_scatsys_irrep_unpack_vector(complex double *target_full,
 
 /// Global translation matrix.
 /**
- * The diagonal (particle self-) block are filled with zeros.
+ * The diagonal (particle self-) block are filled with zeros (even for regular Bessel waves).
  * This may change in the future.
  */
 complex double *qpms_scatsys_build_translation_matrix_full(
diff --git a/qpms/tmatrices.c b/qpms/tmatrices.c
index 0ee828a..2811b87 100644
--- a/qpms/tmatrices.c
+++ b/qpms/tmatrices.c
@@ -616,7 +616,7 @@ complex double *qpms_apply_tmatrix(
     QPMS_CRASHING_CALLOC(f, n, sizeof(complex double));
   const complex double one = 1;
   const complex double zero = 0;
-  cblas_zgemv(CblasRowMajor, CblasNoTrans, n, n, &one, T->m, n, a, 1, &zero, NULL, 1);
+  cblas_zgemv(CblasRowMajor, CblasNoTrans, n, n, &one, T->m, n, a, 1, &zero, f, 1);
   return f;
 }