diff --git a/py/modmath.c b/py/modmath.c
index f2253ab41ef2ca23e2c961f1bcedef82b2422c42..485d9462a965db4437502f70502a6161374ec1d5 100644
--- a/py/modmath.c
+++ b/py/modmath.c
@@ -151,6 +151,7 @@ STATIC const mp_map_elem_t mp_module_math_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_copysign), (mp_obj_t)&mp_math_copysign_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_fabs), (mp_obj_t)&mp_math_fabs_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_floor), (mp_obj_t)&mp_math_floor_obj },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_fmod), (mp_obj_t)&mp_math_fmod_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_frexp), (mp_obj_t)&mp_math_frexp_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ldexp), (mp_obj_t)&mp_math_ldexp_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_modf), (mp_obj_t)&mp_math_modf_obj },
diff --git a/py/nlrx64.S b/py/nlrx64.S
index 55cb4d796039d92640d4543d23ff200a83aec26e..baed6cabd68757910a61a86a6db93551e8af9bbc 100644
--- a/py/nlrx64.S
+++ b/py/nlrx64.S
@@ -32,6 +32,10 @@
 
 #if !defined(__CYGWIN__)
 
+#if (defined(__APPLE__) && defined(__MACH__))
+#define nlr_jump_fail _nlr_jump_fail
+#endif // (defined(__APPLE__) && defined(__MACH__))
+
 /* uint nlr_push(rdi=nlr_buf_t *nlr) */
 #if !(defined(__APPLE__) && defined(__MACH__))
     .globl  nlr_push
diff --git a/py/objexcept.c b/py/objexcept.c
index bf83818b4a29bb91ffd6d5480647539ebf35b90f..0006554a85ea2f47f0bca0d2612523bd9b47cf6a 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -183,11 +183,13 @@ MP_DEFINE_EXCEPTION(Exception, BaseException)
     MP_DEFINE_EXCEPTION(KeyError, LookupError)
   MP_DEFINE_EXCEPTION(MemoryError, Exception)
   MP_DEFINE_EXCEPTION(NameError, Exception)
+    /*
     MP_DEFINE_EXCEPTION_BASE(NameError)
-    //MP_DEFINE_EXCEPTION(UnboundLocalError, NameError)
+    MP_DEFINE_EXCEPTION(UnboundLocalError, NameError)
+    */
   MP_DEFINE_EXCEPTION(OSError, Exception)
-    MP_DEFINE_EXCEPTION_BASE(OSError)
     /*
+    MP_DEFINE_EXCEPTION_BASE(OSError)
     MP_DEFINE_EXCEPTION(BlockingIOError, OSError)
     MP_DEFINE_EXCEPTION(ChildProcessError, OSError)
     MP_DEFINE_EXCEPTION(ConnectionError, OSError)
diff --git a/py/vmentrytable.h b/py/vmentrytable.h
index 217d84d3fd32d7b5d81c3028d3126ab8847f5831..598b5b87260e5eba9321a1b6044d1df737a734ca 100644
--- a/py/vmentrytable.h
+++ b/py/vmentrytable.h
@@ -24,6 +24,11 @@
  * THE SOFTWARE.
  */
 
+#if __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Winitializer-overrides"
+#endif // __clang__
+ 
 static void* entry_table[256] = {
     [0 ... 255] = &&entry_default,
     [MP_BC_LOAD_CONST_FALSE] = &&entry_MP_BC_LOAD_CONST_FALSE,
@@ -110,3 +115,7 @@ static void* entry_table[256] = {
     [MP_BC_IMPORT_FROM] = &&entry_MP_BC_IMPORT_FROM,
     [MP_BC_IMPORT_STAR] = &&entry_MP_BC_IMPORT_STAR,
 };
+
+#if __clang__
+#pragma clang diagnostic pop
+#endif // __clang__
diff --git a/tests/basics/memoryerror.py.exp b/tests/basics/memoryerror.py.exp
new file mode 100644
index 0000000000000000000000000000000000000000..930dbe98d64419ae3e8b384cf71e429d7de9e180
--- /dev/null
+++ b/tests/basics/memoryerror.py.exp
@@ -0,0 +1,2 @@
+MemoryError
+10000 0 9999
diff --git a/unix/Makefile b/unix/Makefile
index b0b037cd7ee8a950efb1bd2d3c7499c96ea9f561..b336892a429d5cd85066e27dbc7fec4f382908e6 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -19,8 +19,8 @@ CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT)
 
 UNAME_S := $(shell uname -s)
  ifeq ($(UNAME_S),Darwin)
-    LDFLAGS = $(LDFLAGS_MOD) -lm -Wl,-map,$@.map
-else
+    LDFLAGS = $(LDFLAGS_MOD) -lm -Wl,-map,$@.map,-order_file,order.def
+ else
     LDFLAGS = $(LDFLAGS_MOD) -lm -Wl,-Map=$@.map,--cref
  endif
 
@@ -71,6 +71,11 @@ SRC_C = \
 	modos.c \
 	$(SRC_MOD)
 
+# Must be the last file
+ifeq ($(UNAME_S),Darwin)
+SRC_C += seg_helpers.c
+endif
+	
 OBJ = $(PY_O) $(addprefix $(BUILD)/, $(SRC_C:.c=.o))
 
 include ../py/mkrules.mk
diff --git a/unix/gccollect.c b/unix/gccollect.c
index 647a1214de6b9658342809dfe9d5e64aa5b50aa0..1b5a38ffc6edd8e3f60a26f78fb7a2b214ef18b3 100644
--- a/unix/gccollect.c
+++ b/unix/gccollect.c
@@ -43,11 +43,17 @@ typedef machine_uint_t regs_t[6];
 
 void gc_helper_get_regs(regs_t arr) {
     register long rbx asm ("rbx");
+    asm("" : "=r"(rbx));
     register long rbp asm ("rbp");
+    asm("" : "=r"(rbp));
     register long r12 asm ("r12");
+    asm("" : "=r"(r12));
     register long r13 asm ("r13");
+    asm("" : "=r"(r13));
     register long r14 asm ("r14");
+    asm("" : "=r"(r14));
     register long r15 asm ("r15");
+    asm("" : "=r"(r15));
     arr[0] = rbx;
     arr[1] = rbp;
     arr[2] = r12;
diff --git a/unix/modsocket.c b/unix/modsocket.c
index 08d0d56b60bc8c50cfb7acf4c01caec7aae46ae5..5192c02438e21f1c03c527a96935be6b1b5d0adb 100644
--- a/unix/modsocket.c
+++ b/unix/modsocket.c
@@ -292,6 +292,7 @@ STATIC const mp_obj_type_t microsocket_type = {
     .locals_dict = (mp_obj_t)&microsocket_locals_dict,
 };
 
+#if MICROPY_SOCKET_EXTRA
 STATIC mp_obj_t mod_socket_htons(mp_obj_t arg) {
     return MP_OBJ_NEW_SMALL_INT((machine_int_t)htons(MP_OBJ_SMALL_INT_VALUE(arg)));
 }
@@ -309,7 +310,6 @@ STATIC mp_obj_t mod_socket_inet_aton(mp_obj_t arg) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_socket_inet_aton_obj, mod_socket_inet_aton);
 
-#if MICROPY_SOCKET_EXTRA
 STATIC mp_obj_t mod_socket_gethostbyname(mp_obj_t arg) {
     assert(MP_OBJ_IS_TYPE(arg, &mp_type_str));
     const char *s = mp_obj_str_get_str(arg);
@@ -322,7 +322,7 @@ STATIC mp_obj_t mod_socket_gethostbyname(mp_obj_t arg) {
     return mp_obj_new_int(*(int*)*h->h_addr_list);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_socket_gethostbyname_obj, mod_socket_gethostbyname);
-#endif
+#endif // MICROPY_SOCKET_EXTRA
 
 STATIC mp_obj_t mod_socket_getaddrinfo(uint n_args, const mp_obj_t *args) {
     // TODO: Implement all args
diff --git a/unix/order.def b/unix/order.def
new file mode 100644
index 0000000000000000000000000000000000000000..34a4fea3e694861f0967d3a127cb0bc8f8ff801a
--- /dev/null
+++ b/unix/order.def
@@ -0,0 +1 @@
+seg_helpers.o: ___bss_start
diff --git a/unix/seg_helpers.c b/unix/seg_helpers.c
new file mode 100644
index 0000000000000000000000000000000000000000..1684f7a8f865d76caae5781db4acb2806d0e3611
--- /dev/null
+++ b/unix/seg_helpers.c
@@ -0,0 +1,38 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/*
+  This is a stub used to create the symbols __bss_start and _end in a Mach-O object file.
+  Thoses are needed by the GC, and should point to the start and end of the bss section.
+  We reach this goal by linking this file last (putting _end at the end...), and using an 
+  order file (order.def) to move __bss_start at the start of bss.
+
+  TODO: Some pragma to do it inline ?
+*/
+
+char __bss_start = 0;
+char _end = 0;
+