diff --git a/C/stdpreds.c b/C/stdpreds.c
index f56a661ad..bc5c26e1d 100644
--- a/C/stdpreds.c
+++ b/C/stdpreds.c
@@ -3949,6 +3949,14 @@ typedef void (*Proc)(void);
 
 Proc E_Modules[]= {/* init_fc,*/ (Proc) 0 };
 
+#ifndef YAPOR
+static
+Int p_yapor_threads(void) {
+  return FALSE;
+}
+#endif
+
+
 void 
 Yap_InitCPreds(void)
 {
@@ -4030,6 +4038,7 @@ Yap_InitCPreds(void)
   Yap_InitCPred("$has_eam", 0, p_has_eam, SafePredFlag|SyncPredFlag|HiddenPredFlag);
 #ifndef YAPOR
   Yap_InitCPred("$default_sequential", 1, p_default_sequential, SafePredFlag|SyncPredFlag|HiddenPredFlag);
+  Yap_InitCPred("$yapor_threads", 1, p_yapor_threads, SafePredFlag|SyncPredFlag|HiddenPredFlag);
 #endif
 #ifdef INES
   Yap_InitCPred("euc_dist", 3, p_euc_dist, SafePredFlag);
@@ -4042,6 +4051,9 @@ Yap_InitCPreds(void)
 #ifdef DEBUG
   Yap_InitCPred("dump_active_goals", 0, p_dump_active_goals, SafePredFlag|SyncPredFlag);
 #endif
+#ifndef YAPOR
+  Yap_InitCPred("dump_active_goals", 0, p_dump_active_goals, SafePredFlag|SyncPredFlag);
+#endif
 
   Yap_InitArrayPreds();
   Yap_InitBBPreds();
diff --git a/OPTYap/opt.preds.c b/OPTYap/opt.preds.c
index ed348d25b..bbe12ebfb 100644
--- a/OPTYap/opt.preds.c
+++ b/OPTYap/opt.preds.c
@@ -125,8 +125,8 @@ static void shm_suspension_frames(long *pages_in_use, long *bytes_in_use);
 ** -------------------------- */
 
 void Yap_init_optyap_preds(void) {
-  Yap_InitCPred("$yapor_threads", 1, p_yapor_threads, SafePredFlag|SyncPredFlag|HiddenPredFlag);
 #ifdef YAPOR
+  Yap_InitCPred("$yapor_threads", 1, p_yapor_threads, SafePredFlag|SyncPredFlag|HiddenPredFlag);
   Yap_InitCPred("$worker", 0, p_worker, SafePredFlag|SyncPredFlag|HiddenPredFlag);
   Yap_InitCPred("$yapor_on", 0, p_yapor_on, SafePredFlag|SyncPredFlag|HiddenPredFlag);
   Yap_InitCPred("$start_yapor", 0, p_start_yapor, SafePredFlag|SyncPredFlag|HiddenPredFlag);