diff --git a/qpms/tmatrices.c b/qpms/tmatrices.c
index 2811b87..1ce435c 100644
--- a/qpms/tmatrices.c
+++ b/qpms/tmatrices.c
@@ -57,7 +57,7 @@ qpms_tmatrix_t *qpms_tmatrix_copy(const qpms_tmatrix_t *T) {
   qpms_tmatrix_t *t = qpms_tmatrix_init(T->spec);
   size_t n = T->spec->n;
   for(size_t i = 0; i < n*n; ++i)
-    t->m = T->m;
+    t->m[i] = T->m[i];
   return t;
 }