diff --git a/mono/metadata/sgen-stw.c b/mono/metadata/sgen-stw.c
index fc1de7c25f87..a249261673f2 100644
--- a/mono/metadata/sgen-stw.c
+++ b/mono/metadata/sgen-stw.c
@@ -28,6 +28,94 @@
 #include "utils/mono-threads.h"
 #include "utils/mono-threads-debug.h"
 
+#if defined (PLATFORM_MACOSX)
+
+#include <dlfcn.h>
+#include <mach-o/dyld.h>
+#include <mach-o/loader.h>
+#include <mach-o/nlist.h>
+#include <pthread.h>
+
+#if defined(__x86_64__)
+
+#define MACH_HEADER_TYPE struct mach_header_64
+#define NLIST_TYPE struct nlist_64
+#define OFFSET_TYPE uint64_t
+
+#elif (defined(i386) || defined(__i386__))
+
+#define MACH_HEADER_TYPE struct mach_header
+#define NLIST_TYPE struct nlist
+#define OFFSET_TYPE uint32_t
+
+#endif
+
+const char *OAExcludeMachThreadID_function_name = "___OAExcludeMachThreadID";
+static void (*OAExcludeMachThreadID) (pthread_t, int) = NULL;
+
+static OFFSET_TYPE
+offset_for_symbol (struct symtab_command *symtab, uint8_t *data, const char *symbol_name)
+{
+	NLIST_TYPE *nlist = (NLIST_TYPE *)(data + symtab->symoff);
+	char *strtab = (char *) (data + symtab->stroff);
+
+	for (int i = 0; i < symtab->nsyms; ++i, nlist++) {
+		const char *name = nlist->n_un.n_strx ? strtab + nlist->n_un.n_strx : NULL;
+		if (name != NULL && strcmp(symbol_name, name) == 0) {
+			OFFSET_TYPE offset = nlist->n_value;
+			return offset;
+		}
+	}
+
+	return 0;
+}
+
+static void
+mono_sgen_dylib_loaded (const struct mach_header *header, intptr_t slide)
+{
+	Dl_info image_info;
+	int result = dladdr(header, &image_info);
+	if (result == 0)
+		return;
+
+	const char *image_name = image_info.dli_fname;
+	if (strstr(image_name, "liboainject.dylib") == NULL)
+		return;
+
+	struct load_command *cmd = (struct load_command*)((char *) header + sizeof(MACH_HEADER_TYPE));
+
+	for (int commandIndex = 0; commandIndex < header->ncmds; commandIndex++) {
+		if (cmd->cmd == LC_SYMTAB) {
+			OFFSET_TYPE offset = offset_for_symbol((struct symtab_command *) cmd, (uint8_t *) header, OAExcludeMachThreadID_function_name);
+			if (offset != 0) {
+				OAExcludeMachThreadID = (void (*)(pthread_t, int)) (slide + offset);
+			}
+
+			return;
+		}
+
+		cmd = (struct load_command *) ((char *) cmd + cmd->cmdsize);
+	}
+}
+
+static void
+mono_sgen_dylib_unloaded (const struct mach_header *header, intptr_t slide)
+{
+	Dl_info image_info;
+	int result = dladdr(header, &image_info);
+	if (result == 0)
+		return;
+
+	const char *image_name = image_info.dli_fname;
+	if (strstr(image_name, "liboainject.dylib") == NULL)
+		return;
+
+	OAExcludeMachThreadID = NULL;
+}
+
+#endif
+
+
 #define TV_DECLARE SGEN_TV_DECLARE
 #define TV_GETTIME SGEN_TV_GETTIME
 #define TV_ELAPSED SGEN_TV_ELAPSED
@@ -132,12 +220,22 @@ sgen_client_stop_world (int generation)
 	sgen_memgov_collection_start (generation);
 	if (sgen_need_bridge_processing ())
 		sgen_bridge_reset_data ();
+
+#if defined (PLATFORM_MACOSX)
+	if (OAExcludeMachThreadID != NULL)
+		OAExcludeMachThreadID(pthread_self(), 1);
+#endif
 }
 
 /* LOCKING: assumes the GC lock is held */
 void
 sgen_client_restart_world (int generation, gint64 *stw_time)
 {
+#if defined (PLATFORM_MACOSX)
+	if (OAExcludeMachThreadID != NULL)
+		OAExcludeMachThreadID(pthread_self(), 0);
+#endif
+
 	TV_DECLARE (end_sw);
 	TV_DECLARE (start_handshake);
 	unsigned long usec;
@@ -186,6 +284,11 @@ mono_sgen_init_stw (void)
 {
 	mono_counters_register ("World stop", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_stop_world);
 	mono_counters_register ("World restart", MONO_COUNTER_GC | MONO_COUNTER_ULONG | MONO_COUNTER_TIME, &time_restart_world);
+
+#if defined (PLATFORM_MACOSX)
+	_dyld_register_func_for_add_image (&mono_sgen_dylib_loaded);
+	_dyld_register_func_for_remove_image (&mono_sgen_dylib_unloaded);
+#endif
 }
 
 /* Unified suspend code */