diff --git a/C/absmi.c b/C/absmi.c
index d337332ca..dbdec12f1 100755
--- a/C/absmi.c
+++ b/C/absmi.c
@@ -1493,12 +1493,16 @@ spy_goal( USES_REGS1 )
   HR += 2;
   {
     PredEntry *pt0;
+#if THREADS
     LOCK(GLOBAL_ThreadHandlesLock);
+#endif
     pt0 = SpyCode;
     P_before_spy = P;
     P = pt0->CodeOfPred;
     /* for profiler */
+#if THREADS
     UNLOCK(GLOBAL_ThreadHandlesLock);
+#endif
 #ifdef LOW_LEVEL_TRACER
     if (Yap_do_low_level_trace)
       low_level_trace(enter_pred,pt0,XREGS+1);
diff --git a/C/c_interface.c b/C/c_interface.c
index 8137800a0..65b8b5a54 100755
--- a/C/c_interface.c
+++ b/C/c_interface.c
@@ -3096,7 +3096,7 @@ YAP_Init(YAP_init_args *yap_init)
       /* slaves, waiting for work */
       CurrentModule = USER_MODULE;
       P = GETWORK_FIRST_TIME;
-      Yap_exec_absmi(FALSE);
+      Yap_exec_absmi(FALSE,  YAP_EXEC_ABSMI);
       Yap_Error(INTERNAL_ERROR, TermNil, "abstract machine unexpected exit (YAP_Init)");
     }
 #endif /* YAPOR */
diff --git a/H/dlmalloc.h b/H/dlmalloc.h
index de84b3df2..1df96e7ef 100644
--- a/H/dlmalloc.h
+++ b/H/dlmalloc.h
@@ -179,8 +179,10 @@ extern "C" {
 #if DEBUG_DLMALLOC
 #include <assert.h>
 #else
+#ifndef assert
 #define assert(x) ((void)0)
 #endif
+#endif
 
 /*
   The unsigned integer type used for comparing any two chunk sizes.
diff --git a/OPTYap/locks_x86.h b/OPTYap/locks_x86.h
index ca0c42caa..012972a6b 100644
--- a/OPTYap/locks_x86.h
+++ b/OPTYap/locks_x86.h
@@ -71,10 +71,10 @@ extern int debug_locks;
 		      __BASE_FILE__, __LINE__,&(LOCK_VAR)); \
 	     spin_unlock((spinlock_t *)&(LOCK_VAR))
 #else
-#define LOCK(LOCK_VAR)         do {	\
+#define LOCK(LOCK_VAR)         { do {					\
                                  if (TRY_LOCK(&(LOCK_VAR))) break;      \
 		                 while (IS_LOCKED(LOCK_VAR)) continue;  \
-                               } while (1)
+				 } while (1); }
 #define IS_LOCKED(LOCK_VAR)    ((LOCK_VAR) != 0)
 #define IS_UNLOCKED(LOCK_VAR)  ((LOCK_VAR) == 0)
 #define UNLOCK(LOCK_VAR)       spin_unlock((spinlock_t *)&(LOCK_VAR))