diff --git a/include/mimalloc/prim.h b/include/mimalloc/prim.h
index 89266817..4ee6d43f 100644
--- a/include/mimalloc/prim.h
+++ b/include/mimalloc/prim.h
@@ -130,8 +130,9 @@ void _mi_prim_thread_associate_default_heap(mi_heap_t* heap);
 // If you test on another platform and it works please send a PR :-)
 // see also https://akkadia.org/drepper/tls.pdf for more info on the TLS register.
 //
-// Note: on most platforms this is not actually used anymore as we prefer `__builtin_thread_pointer()` nowadays.
-// However, we do still use it with older clang compilers and Apple OS (as we use TLS slot for the default heap there).
+// Note: we would like to prefer `__builtin_thread_pointer()` nowadays instead of using assembly,
+// but unfortunately we can not detect support reliably (see issue #883)
+// We also use it on Apple OS as we use a TLS slot for the default heap there.
 #if defined(__GNUC__) && ( \
            (defined(__GLIBC__)   && (defined(__x86_64__) || defined(__i386__) || defined(__arm__) || defined(__aarch64__))) \
         || (defined(__APPLE__)   && (defined(__x86_64__) || defined(__aarch64__) || defined(__POWERPC__))) \
diff --git a/src/alloc-override.c b/src/alloc-override.c
index 75afc202..12837cdd 100644
--- a/src/alloc-override.c
+++ b/src/alloc-override.c
@@ -136,8 +136,11 @@ typedef void* mi_nothrow_t;
   mi_decl_export void* realloc(void* p, size_t newsize) MI_FORWARD2(mi_realloc, p, newsize)
   mi_decl_export void  free(void* p)                    MI_FORWARD0(mi_free, p)  
   // In principle we do not need to forward `strdup`/`strndup` but on some systems these do not use `malloc` internally (but a more primitive call)
+  // We only override if `strdup` is not a macro (as on some older libc's, see issue #885)
+  #if !defined(strdup)
   mi_decl_export char* strdup(const char* str)             MI_FORWARD1(mi_strdup, str)
-  #if !defined(__APPLE__) || (defined(MAC_OS_X_VERSION_10_7) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7)
+  #endif
+  #if !defined(strndup) && (!defined(__APPLE__) || (defined(MAC_OS_X_VERSION_10_7) && MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7))
   mi_decl_export char* strndup(const char* str, size_t n)  MI_FORWARD2(mi_strndup, str, n)   
   #endif
 #endif