diff --git a/compiler/semalias.nim b/compiler/semalias.nim
index 75bd4005bebb9..91c7eabd14a91 100644
--- a/compiler/semalias.nim
+++ b/compiler/semalias.nim
@@ -1,5 +1,6 @@
 import "."/[ast,options]
 
+{.emit: "NIM_EXTERNC".} # for bootstrapping; remove after 0.21, refs #12144
 proc isMacroRealGeneric*(s: PSym): bool {.exportc.} =
   if s.kind != skMacro: return false
   if s.ast == nil: return false
diff --git a/compiler/semtypes.nim b/compiler/semtypes.nim
index 061fa8d001218..4d933ded4f22e 100644
--- a/compiler/semtypes.nim
+++ b/compiler/semtypes.nim
@@ -988,7 +988,7 @@ proc liftParamType(c: PContext, procKind: TSymKind, genericParams: PNode,
       # aliasSym are not bindOnce
       paramTypId = nil
       let t = newTypeS(tyAliasSym, c)
-      result = addImplicitGeneric(t)
+      result = addImplicitGeneric(c, t, paramTypId, info, genericParams, paramName)
       if result != nil: result.flags.incl({tfUnresolved})
 
   of tyDistinct: