diff --git a/milkymist/framebuffer/__init__.py b/milkymist/framebuffer/__init__.py
index d0dea5fa6..4106ce8cd 100644
--- a/milkymist/framebuffer/__init__.py
+++ b/milkymist/framebuffer/__init__.py
@@ -1,4 +1,5 @@
 from migen.fhdl.structure import *
+from migen.fhdl.specials import Instance
 from migen.flow.actor import *
 from migen.flow.network import *
 from migen.flow.transactions import *
@@ -155,7 +156,7 @@ class FIFO(Actor):
 				
 				self.busy.eq(0)
 			],
-			instances=[asfifo])
+			specials={asfifo})
 
 def sim_fifo_gen():
 	while True:
diff --git a/milkymist/lm32/__init__.py b/milkymist/lm32/__init__.py
index cc2c6ed72..e2c743f98 100644
--- a/milkymist/lm32/__init__.py
+++ b/milkymist/lm32/__init__.py
@@ -1,4 +1,5 @@
 from migen.fhdl.structure import *
+from migen.fhdl.specials import Instance
 from migen.bus import wishbone
 
 class LM32:
@@ -49,4 +50,4 @@ class LM32:
 			self.ibus.adr.eq(self._i_adr_o[2:]),
 			self.dbus.adr.eq(self._d_adr_o[2:])
 		]
-		return Fragment(comb=comb, instances=[self._inst])
+		return Fragment(comb, specials={self._inst})
diff --git a/milkymist/m1crg/__init__.py b/milkymist/m1crg/__init__.py
index cd8a78f6d..baef94975 100644
--- a/milkymist/m1crg/__init__.py
+++ b/milkymist/m1crg/__init__.py
@@ -1,6 +1,7 @@
 from fractions import Fraction
 
 from migen.fhdl.structure import *
+from migen.fhdl.specials import Instance
 from mibuild.crg import CRG
 
 class M1CRG(CRG):
@@ -58,4 +59,4 @@ class M1CRG(CRG):
 		self._inst = Instance("m1crg", *inst_items)
 
 	def get_fragment(self):
-		return Fragment(instances=[self._inst])
+		return Fragment(specials={self._inst})
diff --git a/milkymist/minimac3/__init__.py b/milkymist/minimac3/__init__.py
index dff85a513..8c8d68d40 100644
--- a/milkymist/minimac3/__init__.py
+++ b/milkymist/minimac3/__init__.py
@@ -1,4 +1,5 @@
 from migen.fhdl.structure import *
+from migen.fhdl.specials import Instance
 from migen.bank.description import *
 from migen.bank.eventmanager import *
 from migen.bank import csrgen
@@ -59,8 +60,7 @@ class MiniMAC:
 			rx_pending_0_r.eq(rx_pending_0),
 			rx_pending_1_r.eq(rx_pending_1)
 		]
-		inst = [
-			Instance("minimac3",
+		inst = Instance("minimac3",
 				Instance.ClockPort("sys_clk"),
 				Instance.ResetPort("sys_rst"),
 
@@ -94,7 +94,6 @@ class MiniMAC:
 				Instance.Input("phy_rx_er", self.phy_rx_er),
 				Instance.Input("phy_col", self.phy_col),
 				Instance.Input("phy_crs", self.phy_crs))
-		]
-		return Fragment(comb, sync, instances=inst) \
+		return Fragment(comb, sync, specials={inst}) \
 			+ self.events.get_fragment() \
 			+ self.bank.get_fragment()
diff --git a/milkymist/s6ddrphy/__init__.py b/milkymist/s6ddrphy/__init__.py
index 882af43d3..3f16baf1f 100644
--- a/milkymist/s6ddrphy/__init__.py
+++ b/milkymist/s6ddrphy/__init__.py
@@ -1,4 +1,5 @@
 from migen.fhdl.structure import *
+from migen.fhdl.specials import Instance
 from migen.bus import dfi
 
 class S6DDRPHY:
@@ -41,4 +42,4 @@ class S6DDRPHY:
 		self._inst = Instance("s6ddrphy", *inst_items)
 
 	def get_fragment(self):
-		return Fragment(instances=[self._inst])
+		return Fragment(specials={self._inst})