diff --git a/fpga/__init__.py b/fpga/__init__.py
index 6b29208..48e0ec3 100644
--- a/fpga/__init__.py
+++ b/fpga/__init__.py
@@ -6,16 +6,18 @@ __version__ = '0.1.0'
 def populate_environ():
     import os, shutil
 
-    for env_name, program in [
-            ("YOSYS",         "yowasp-yosys"),
-            ("NEXTPNR_ICE40", "yowasp-nextpnr-ice40"),
-            ("NEXTPNR_ECP5",  "yowasp-nextpnr-ecp5"),
+    for nmigen_envvar, expected_path, alternative_path in [
+            ("YOSYS",         "yosys",         "yowasp-yosys"), # nmigen-yosys is handled by nmigen
+            ("NEXTPNR_ICE40", "nextpnr-ice40", "yowasp-nextpnr-ice40"),
+            ("NEXTPNR_ECP5",  "nextpnr-ecp5",  "yowasp-nextpnr-ecp5"),
         ]:
-        if shutil.which(program):
-            os.environ[env_name] = program
+        if nmigen_envvar in os.environ: continue
+        if shutil.which(expected_path): continue
+        if not shutil.which(alternative_path): continue
+        os.environ[nmigen_envvar] = alternative_path
 
 populate_environ()
 del populate_environ
 
 # dogelang: Slow. Stupid. Absolutely adorable.
-import dg # install import hook
+import dg # setup the dg import hook