diff --git a/imagepy/tools/Measure/profile_tol.py b/imagepy/tools/Measure/profile_tol.py
index 3bd0ed48..035e1acf 100644
--- a/imagepy/tools/Measure/profile_tol.py
+++ b/imagepy/tools/Measure/profile_tol.py
@@ -131,8 +131,8 @@ def profile(self, body, img):
         (x1, y1), (x2, y2) = body[0]
         dx, dy = x2-x1, y2-y1
         n = max(abs(dx), abs(dy)) + 1
-        xs = np.linspace(x1, x2, n).round().astype(np.int16)
-        ys = np.linspace(y1, y2, n).round().astype(np.int16)
+        xs = np.linspace(x1, x2, int(n)).round().astype(np.int16)
+        ys = np.linspace(y1, y2, int(n)).round().astype(np.int16)
         msk = (xs>=0) * (xs<img.shape[1])
         msk*= (ys>=0) * (ys<img.shape[0])
         ix = np.arange(len(xs))
diff --git a/imagepy/tools/Network/graphcut_tol.py b/imagepy/tools/Network/graphcut_tol.py
index 2acad92b..0f64e1e3 100644
--- a/imagepy/tools/Network/graphcut_tol.py
+++ b/imagepy/tools/Network/graphcut_tol.py
@@ -41,8 +41,8 @@ def cut(img, lines):
         cx, cy = i
         dx, dy = cx-ox, cy-oy
         n = max(abs(dx), abs(dy)) + 1
-        xs = np.linspace(cx, ox, n).round().astype(np.int16)
-        ys = np.linspace(cy, oy, n).round().astype(np.int16)
+        xs = np.linspace(cx, ox, n.astype(np.uint16)).round().astype(np.int16)
+        ys = np.linspace(cy, oy, n.astype(np.uint16)).round().astype(np.int16)
         for x,y in zip(xs, ys):
             for dxy in [(1,0),(0,1)]:
                 xx = x + dxy[0]
diff --git a/imagepy/tools/Network/graphpen_tol.py b/imagepy/tools/Network/graphpen_tol.py
index 0ca8584a..ecd38a4e 100644
--- a/imagepy/tools/Network/graphpen_tol.py
+++ b/imagepy/tools/Network/graphpen_tol.py
@@ -42,8 +42,8 @@ def draw(img, lines):
         cx, cy = i
         dx, dy = cx-ox, cy-oy
         n = max(abs(dx), abs(dy)) + 1
-        xs = np.linspace(ox, cx, n).round().astype(np.int16)
-        ys = np.linspace(oy, cy, n).round().astype(np.int16)
+        xs = np.linspace(ox, cx, n.astype(np.uint16)).round().astype(np.int16)
+        ys = np.linspace(oy, cy, n.astype(np.uint16)).round().astype(np.int16)
         for x,y in zip(xs, ys):
             if x<0 or x>img.shape[1]: continue
             if y<0 or y>img.shape[0]: continue
diff --git a/imagepy/widgets/histogram/channels_wgt.py b/imagepy/widgets/histogram/channels_wgt.py
index 9ea50f45..93e16f17 100644
--- a/imagepy/widgets/histogram/channels_wgt.py
+++ b/imagepy/widgets/histogram/channels_wgt.py
@@ -172,6 +172,7 @@ def on_setback(self, event):
 		name = self.com_back.GetValue()
 		if name is None: return
 		ImageManager.get().back = ImageManager.get(name)
+		curwin = WindowsManager.get()
 		curwin.ips.update()
 
 	def on_mode(self, event):