diff --git a/kwant/graph/c_slicer.pxd b/kwant/graph/c_slicer.pxd
index 67a45c0490ce4133107338233fc49b608498ae91..9e692a55bc68e3328a606270c104cedec877779f 100644
--- a/kwant/graph/c_slicer.pxd
+++ b/kwant/graph/c_slicer.pxd
@@ -11,7 +11,8 @@ from defs cimport gint
 cdef extern from "c_slicer/slicer.h":
     struct Slicing:
         int nslices
-        int *slice_ptr, *slices
+        int *slice_ptr
+        int *slices
 
     Slicing *slice(gint, gint *, gint *, gint, gint *,
                    gint, gint *)
diff --git a/kwant/graph/core.pyx b/kwant/graph/core.pyx
index d76bb36f8af3e75eb5839bd344efa62801f6bd7c..c60d5165659d02c21eecbfd72eca1992ab616216 100644
--- a/kwant/graph/core.pyx
+++ b/kwant/graph/core.pyx
@@ -202,8 +202,10 @@ cdef class Graph:
                                                   self.num_pp_edges,
                                                   self.num_pn_edges,
                                                   self.num_np_edges)
-        cdef gint *hbuf = result.heads_idxs + 1, *heads = result.heads
-        cdef gint *tbuf = result.tails_idxs + 1, *tails = result.tails
+        cdef gint *hbuf = result.heads_idxs + 1
+        cdef gint *heads = result.heads
+        cdef gint *tbuf = result.tails_idxs + 1
+        cdef gint *tails = result.tails
         cdef gint *edge_ids = result.edge_ids
         cdef gint edge_id = 0, num_edges     # = 0 is there to silence warning.
         cdef Edge *edge
diff --git a/kwant/linalg/cmumps.pxd b/kwant/linalg/cmumps.pxd
index 29785c1bee14df9da46bd4d5785061fc938969d9..1d60a3eeeb1fd7c76b1878f5cd09a097071aa11b 100644
--- a/kwant/linalg/cmumps.pxd
+++ b/kwant/linalg/cmumps.pxd
@@ -45,8 +45,10 @@ cdef extern from "zmumps_c.h":
         MUMPS_INT nrhs, lrhs
         ZMUMPS_COMPLEX *rhs
 
-        MUMPS_INT info[40], infog[40]
-        ZMUMPS_REAL rinfo[40], rinfog[40]
+        MUMPS_INT info[40]
+        MUMPS_INT infog[40]
+        ZMUMPS_REAL rinfo[40]
+        ZMUMPS_REAL rinfog[40]
 
         MUMPS_INT nz_rhs
         ZMUMPS_COMPLEX *rhs_sparse