diff --git a/skimage/morphology/ccomp.pxd b/skimage/morphology/ccomp.pxd
index 569921fa..62d21fec 100644
--- a/skimage/morphology/ccomp.pxd
+++ b/skimage/morphology/ccomp.pxd
@@ -5,6 +5,6 @@ DTYPE = cnp.intp
 ctypedef cnp.intp_t DTYPE_t
 
 cdef DTYPE_t find_root(DTYPE_t *forest, DTYPE_t n)
-cdef set_root(DTYPE_t *forest, DTYPE_t n, DTYPE_t root)
-cdef join_trees(DTYPE_t *forest, DTYPE_t n, DTYPE_t m)
-cdef link_bg(DTYPE_t *forest, DTYPE_t n, DTYPE_t *background_node)
+cdef void set_root(DTYPE_t *forest, DTYPE_t n, DTYPE_t root)
+cdef void join_trees(DTYPE_t *forest, DTYPE_t n, DTYPE_t m)
+cdef void link_bg(DTYPE_t *forest, DTYPE_t n, DTYPE_t *background_node)
diff --git a/skimage/morphology/ccomp.pyx b/skimage/morphology/ccomp.pyx
index 1db78a6d..5d449e62 100644
--- a/skimage/morphology/ccomp.pyx
+++ b/skimage/morphology/ccomp.pyx
@@ -39,7 +39,7 @@ cdef DTYPE_t find_root(DTYPE_t *forest, DTYPE_t n):
     return root
 
 
-cdef set_root(DTYPE_t *forest, DTYPE_t n, DTYPE_t root):
+cdef inline void set_root(DTYPE_t *forest, DTYPE_t n, DTYPE_t root):
     """
     Set all nodes on a path to point to new_root.
 
@@ -53,7 +53,7 @@ cdef set_root(DTYPE_t *forest, DTYPE_t n, DTYPE_t root):
     forest[n] = root
 
 
-cdef join_trees(DTYPE_t *forest, DTYPE_t n, DTYPE_t m):
+cdef inline void join_trees(DTYPE_t *forest, DTYPE_t n, DTYPE_t m):
     """Join two trees containing nodes n and m.
 
     """
@@ -70,7 +70,7 @@ cdef join_trees(DTYPE_t *forest, DTYPE_t n, DTYPE_t m):
         set_root(forest, m, root)
 
 
-cdef link_bg(DTYPE_t *forest, DTYPE_t n, DTYPE_t *background_node):
+cdef inline void link_bg(DTYPE_t *forest, DTYPE_t n, DTYPE_t *background_node):
     """
     Link a node to the background node.
 
@@ -80,8 +80,8 @@ cdef link_bg(DTYPE_t *forest, DTYPE_t n, DTYPE_t *background_node):
 
     join_trees(forest, n, background_node[0])
 
-# Connected components search as described in Fiorio et al.
 
+# Connected components search as described in Fiorio et al.
 def label(input, DTYPE_t neighbors=8, DTYPE_t background=-1):
     """Label connected regions of an integer array.
 
@@ -202,7 +202,6 @@ def label(input, DTYPE_t neighbors=8, DTYPE_t background=-1):
                 join_trees(forest_p, i*cols + j, i*cols + j - 1)
 
     # Label output
-
     cdef DTYPE_t ctr = 0
     for i in range(rows):
         for j in range(cols):