diff --git a/litex/compat/__init__.py b/litex/compat/__init__.py
index 34e5cf2fb..72357f3eb 100644
--- a/litex/compat/__init__.py
+++ b/litex/compat/__init__.py
@@ -1,6 +1,8 @@
 import sys
 import time
 
+# Helpers ------------------------------------------------------------------------------------------
+
 def colorer(s, color="bright"): # FIXME: Move colorer to litex.common?
     header  = {
         "bright": "\x1b[1m",
@@ -12,6 +14,8 @@ def colorer(s, color="bright"): # FIXME: Move colorer to litex.common?
     trailer = "\x1b[0m"
     return header + str(s) + trailer
 
+# Compat -------------------------------------------------------------------------------------------
+
 def compat_notice(name, date, info=""):
     print("Compat: {name} is {deprecated} since {date} and will soon no longer work, please {update}. {info}".format(
         name       = colorer(name),
@@ -26,14 +30,28 @@ def compat_notice(name, date, info=""):
         print(".", end="")
         sys.stdout.flush()
     print("thanks :)")
-    time.sleep(1)
 
 def add_compat(location):
+    # Integration.
     if location == "litex.soc.integration":
-        #compat_notice("SoCSDRAM", date="2020-03-24", info="Switch to SoCCore/add_sdram/soc_core_args instead.")
-        from litex.compat import soc_sdram
-        sys.modules["litex.soc.integration.soc_sdram"] = soc_sdram
+        class compat_soc_sdram:
+            noticed = False
+            def __getattr__(self, name):
+                if not self.noticed:
+                    compat_notice("SoCSDRAM", date="2020-03-24", info="Switch to SoCCore/add_sdram/soc_core_args instead.")
+                    self.noticed = True
+                from litex.compat import soc_sdram
+                return getattr(soc_sdram, name)
+        sys.modules["litex.soc.integration.soc_sdram"] = compat_soc_sdram()
+    # Cores.
     elif location == "litex.soc.cores":
-        compat_notice("litex.soc.cores.up5kspram", date="2020-03-24", info="Switch to litex.soc.cores.ram.")
+        class compat_up5kspram:
+            noticed = False
+            def __getattr__(self, name):
+                if not self.noticed:
+                    compat_notice("litex.soc.cores.up5kspram", date="2020-03-24", info="Switch to litex.soc.cores.ram.")
+                    self.noticed = True
+                from litex.soc.cores import ram
+                return getattr(ram, name)
         from litex.soc.cores import ram
-        sys.modules["litex.soc.cores.up5kspram"] = ram
+        sys.modules["litex.soc.cores.up5kspram"] = compat_up5kspram()