diff --git a/C/adtdefs.c b/C/adtdefs.c
index 15cbbb636..95adc53ca 100644
--- a/C/adtdefs.c
+++ b/C/adtdefs.c
@@ -991,8 +991,14 @@ Yap_PredPropByFunctorNonThreadLocal(Functor f, Term cur_mod)
     return Yap_NewPredPropByFunctor(f,cur_mod);
 
   if ((p->ModuleOfPred == cur_mod || !(p->ModuleOfPred))) {
-    WRITE_UNLOCK(f->FRWLock);
-    return AbsPredProp(p);
+    /* don't match multi-files */
+    if (!(p->PredFlags & MultiFileFlag) ||
+	p->ModuleOfPred ||
+	!cur_mod ||
+	cur_mod == TermProlog) {
+      WRITE_UNLOCK(f->FRWLock);
+      return AbsPredProp(p);
+    }
   }
   if (p->NextOfPE) {
     UInt hash = PRED_HASH(f,cur_mod,PredHashTableSize);
@@ -1027,8 +1033,14 @@ Yap_PredPropByAtomNonThreadLocal(Atom at, Term cur_mod)
     PredEntry *pe = RepPredProp(p0);
     if ( pe->KindOfPE == PEProp && 
 	 (pe->ModuleOfPred == cur_mod || !pe->ModuleOfPred)) {
-      WRITE_UNLOCK(ae->ARWLock);
-      return(p0);
+      /* don't match multi-files */
+      if (!(pe->PredFlags & MultiFileFlag) ||
+	  pe->ModuleOfPred ||
+	  !cur_mod ||
+	  cur_mod == TermProlog) {
+	WRITE_UNLOCK(ae->ARWLock);
+	return(p0);
+      }
     }
     p0 = pe->NextOfPE;
   }
diff --git a/C/cdmgr.c b/C/cdmgr.c
index e0234f3cc..81d88da0c 100644
--- a/C/cdmgr.c
+++ b/C/cdmgr.c
@@ -2136,9 +2136,9 @@ addclause(Term t, yamop *cp, int mode, Term mod, Term *t4ref)
   PELOCK(20,p);
   pflags = p->PredFlags;
   /* we are redefining a prolog module predicate */
-  if ((pflags &
-       (UserCPredFlag|CArgsPredFlag|NumberDBPredFlag|AtomDBPredFlag|TestPredFlag|AsmPredFlag|CPredFlag|BinaryPredFlag)) ||
-      (p->ModuleOfPred == PROLOG_MODULE && mod != TermProlog && mod && !(p->PredFlags & (DynamicPredFlag|LogUpdatePredFlag|MultiFileFlag)))) {
+  if ((pflags & (UserCPredFlag|CArgsPredFlag|NumberDBPredFlag|AtomDBPredFlag|TestPredFlag|AsmPredFlag|CPredFlag|BinaryPredFlag)) ||
+      (p->ModuleOfPred == PROLOG_MODULE && 
+       mod != TermProlog && mod) ) {
     addcl_permission_error(RepAtom(at), Arity, FALSE);
     UNLOCKPE(30,p);
     return TermNil;
@@ -2884,6 +2884,9 @@ p_new_multifile( USES_REGS1 )
     pe = RepPredProp(PredPropByFunc(Yap_MkFunctor(at, arity),mod));
   PELOCK(26,pe);
   pe->PredFlags |= MultiFileFlag;
+  /* mutifile-predicates are weird, they do not seat really on the default module */
+  if (pe->ModuleOfPred == PROLOG_MODULE)
+    pe->ModuleOfPred = TermProlog;
   if (!(pe->PredFlags & (DynamicPredFlag|LogUpdatePredFlag))) {
     /* static */
     pe->PredFlags |= (SourcePredFlag|CompiledPredFlag);
diff --git a/C/qlyr.c b/C/qlyr.c
index 14f5b344a..acd6ada0a 100644
--- a/C/qlyr.c
+++ b/C/qlyr.c
@@ -906,6 +906,9 @@ read_pred(IOSTREAM *stream, Term mod) {
       ap->src.OwnerFile = AtomAdjust(ap->src.OwnerFile);
     }
   }
+  /* multifile predicates cannot reside in module 0 */
+  if (flags & MultiFileFlag && ap->ModuleOfPred == PROLOG_MODULE)
+    ap->ModuleOfPred = TermProlog;
   read_clauses(stream, ap, nclauses, flags);
 }