diff --git a/C/dbase.c b/C/dbase.c
index defedf993..383853cec 100644
--- a/C/dbase.c
+++ b/C/dbase.c
@@ -2652,7 +2652,6 @@ new_lu_int_key(Int key)
   p->ArityOfPE = 3;
   p->OpcodeOfPred = Yap_opcode(_op_fail);
   p->cs.p_code.TrueCodeOfPred = p->CodeOfPred = FAILCODE;
-  WRITE_UNLOCK(ae->ARWLock);
   INT_LU_KEYS[hash_key] = p0;
   return p;
 }
diff --git a/C/utilpreds.c b/C/utilpreds.c
index f35052384..bca2c62b1 100644
--- a/C/utilpreds.c
+++ b/C/utilpreds.c
@@ -1990,6 +1990,10 @@ AddAtomToHash(CELL *st, Atom at)
   } else {
     char *c = RepAtom(at)->StrOfAE;
     int ulen = strlen(c);
+    /* fix hashing over empty atom */
+    if (!ulen) {
+      return st;
+    }
     start = (CELL *)c;
     if (ulen % CellSize == 0) {
       len = ulen/CellSize;
diff --git a/H/Yap.h b/H/Yap.h
index 630326d71..7821833d1 100644
--- a/H/Yap.h
+++ b/H/Yap.h
@@ -145,8 +145,10 @@
 
 #ifdef THREADS
 #if USE_PTHREAD_LOCKING
+#ifndef _XOPEN_SOURCE
 #define _XOPEN_SOURCE 600
 #endif
+#endif
 #include <pthread.h>
 #endif
 
diff --git a/packages/clpqr b/packages/clpqr
index 0072deb51..e3ee70d59 160000
--- a/packages/clpqr
+++ b/packages/clpqr
@@ -1 +1 @@
-Subproject commit 0072deb511e839a2f2df6bfa170076f9c8ecb6bb
+Subproject commit e3ee70d5971a5af8c9a2a3a5fe8a1892c3777f2b
diff --git a/packages/jpl b/packages/jpl
index 8192d5f9b..d661852f7 160000
--- a/packages/jpl
+++ b/packages/jpl
@@ -1 +1 @@
-Subproject commit 8192d5f9ba0bba55fdd96b4473d68d8cf57f51aa
+Subproject commit d661852f76fe24441d983ef6f4e60ba90cfe17c4