diff --git a/compiler/ast.nim b/compiler/ast.nim
index bc28cff845..bafc02dba2 100644
--- a/compiler/ast.nim
+++ b/compiler/ast.nim
@@ -1680,3 +1680,10 @@ type
 
 template initSymMapping*(): SymMapping = initIdTable[PSym]()
 template initTypeMapping*(): TypeMapping = initIdTable[PType]()
+
+proc sameModules*(a, b: PSym): bool {.inline.} =
+  assert a.kind == skModule and b.kind == skModule
+  result = a.position == b.position
+
+proc sameOwners*(a, b: PSym): bool =
+  result = a == b or (a.kind == skModule and b.kind == skModule and a.position == b.position) or a.id == b.id
diff --git a/compiler/cgen.nim b/compiler/cgen.nim
index b380b136d2..591979aea1 100644
--- a/compiler/cgen.nim
+++ b/compiler/cgen.nim
@@ -1543,7 +1543,7 @@ proc genProcLvl2(m: BModule, prc: PSym) =
     # externally-to-the-current-module defined proc, also important
     # to do the declaredProtos check before the call to genProcPrototype
     if isReloadable(m, prc) and prc.id notin m.declaredProtos and
-      q != nil and q.module.id != m.module.id:
+      q != nil and not sameModules(q.module, m.module):
       m.s[cfsDynLibInit].add('\t')
       m.s[cfsDynLibInit].addAssignment(prc.loc.snippet,
         cCast(getProcTypeCast(m, prc),
@@ -1601,7 +1601,7 @@ proc genVarPrototype(m: BModule, n: PNode) =
 
   if (lfNoDecl in sym.loc.flags) or contains(m.declaredThings, sym.id):
     return
-  if sym.owner.id != m.module.id:
+  if not sameOwners(sym.owner, m.module):
     # else we already have the symbol generated!
     assert(sym.loc.snippet != "")
     incl(m.declaredThings, sym.id)
diff --git a/compiler/nifbackend.nim b/compiler/nifbackend.nim
index 39da0d762e..fa293bbfe3 100644
--- a/compiler/nifbackend.nim
+++ b/compiler/nifbackend.nim
@@ -131,11 +131,18 @@ proc generateCode*(g: ModuleGraph; mainFileIdx: FileIndex) =
   # during code generation of `main.nim` we can trigger the code generation
   # of symbols in different modules so we need to finish these modules
   # here later, after the above loop!
+  # Important: The main module must be finished LAST so that all other modules
+  # have registered their init procs before genMainProc uses them.
+  var mainModule: BModule = nil
   for m in BModuleList(g.backend).mods:
     if m != nil:
       assert m.module != nil
-      #if sfMainModule notin m.module.flags:
-      finishModule g, m
+      if sfMainModule in m.module.flags:
+        mainModule = m
+      else:
+        finishModule g, m
+  if mainModule != nil:
+    finishModule g, mainModule
 
   # Write C files
   cgenWriteModules(g.backend, g.config)
diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
index c86af27c91..be9e409108 100644
--- a/compiler/semstmts.nim
+++ b/compiler/semstmts.nim
@@ -2361,7 +2361,7 @@ proc semCppMember(c: PContext; s: PSym; n: PNode) =
         typ = typ.elementType
       if typ.kind != tyObject:
         localError(c.config, n.info, pragmaName & " must be either ptr to object or object type.")
-      if typ.owner.id == s.owner.id and c.module.id == s.owner.id:
+      if sameOwners(typ.owner, s.owner) and sameOwners(c.module, s.owner):
         c.graph.memberProcsPerType.mgetOrPut(typ.itemId, @[]).add s
       else:
         localError(c.config, n.info,
diff --git a/compiler/suggest.nim b/compiler/suggest.nim
index 5c3265dba2..a1cd8b9237 100644
--- a/compiler/suggest.nim
+++ b/compiler/suggest.nim
@@ -356,12 +356,12 @@ proc filterSymNoOpr(s: PSym; prefix: PNode; res: var PrefixMatch): bool {.inline
      not isKeyword(s.name)
 
 proc fieldVisible*(c: PContext, f: PSym): bool {.inline.} =
-  let fmoduleId = getModule(f).id
-  result = sfExported in f.flags or fmoduleId == c.module.id
+  let fmodule = getModule(f)
+  result = sfExported in f.flags or sameModules(fmodule, c.module)
 
   if not result:
     for module in c.friendModules:
-      if fmoduleId == module.id: return true
+      if sameModules(fmodule, module): return true
     if f.kind == skField:
       var symObj = f.owner.typ.toObjectFromRefPtrGeneric.sym
       assert symObj != nil