diff --git a/include/thread.h b/include/thread.h
index 2318beb4d..713fe9064 100644
--- a/include/thread.h
+++ b/include/thread.h
@@ -18,7 +18,7 @@
 
 #if defined (_WIN)
 
-#define hc_thread_create(t,T,f,a)   t = CreateThread (T, 0, (LPTHREAD_START_ROUTINE) &f, a, 0, NULL)
+#define hc_thread_create(t,f,a)     t = CreateThread (NULL, 0, (LPTHREAD_START_ROUTINE) &f, a, 0, NULL)
 #define hc_thread_wait(n,a)         for (u32 i = 0; i < n; i++) WaitForSingleObject ((a)[i], INFINITE)
 #define hc_thread_exit(t)           ExitThread (t)
 
@@ -29,7 +29,7 @@
 
 #elif defined (_POSIX)
 
-#define hc_thread_create(t,T,f,a)   pthread_create (&t, T, f, a)
+#define hc_thread_create(t,f,a)     pthread_create (&t, NULL, f, a)
 #define hc_thread_wait(n,a)         for (u32 i = 0; i < n; i++) pthread_join ((a)[i], NULL)
 #define hc_thread_exit(t)           pthread_exit (&t)
 
diff --git a/include/types.h b/include/types.h
index 0d7004033..c1025dcf2 100644
--- a/include/types.h
+++ b/include/types.h
@@ -566,6 +566,9 @@ typedef struct hashes
 
   hashinfo_t  **hash_info;
 
+  u8     *out_buf; // allocates [HCBUFSIZ_LARGE];
+  u8     *tmp_buf; // allocates [HCBUFSIZ_LARGE];
+
 } hashes_t;
 
 struct hashconfig
diff --git a/src/Makefile b/src/Makefile
index 9d5b08c84..8e609cdf1 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -126,6 +126,7 @@ CFLAGS                  += -ftrapv
 # default linux and freebsd thread stack size is 2MB
 # default windows thread stack size is 1MB
 # default OSX thread stack size is 512kB
+# unfortionally, this option isn't supported by older GCC and clang versions
 
 CFLAGS                  += -Wstack-usage=524288
 
diff --git a/src/hashcat.c b/src/hashcat.c
index 258d5b855..0671d517b 100644
--- a/src/hashcat.c
+++ b/src/hashcat.c
@@ -178,7 +178,7 @@ static int inner2_loop (hashcat_ctx_t *hashcat_ctx)
     thread_param->hashcat_ctx = hashcat_ctx;
     thread_param->tid         = device_id;
 
-    hc_thread_create (c_threads[device_id], NULL, thread_autotune, thread_param);
+    hc_thread_create (c_threads[device_id], thread_autotune, thread_param);
   }
 
   hc_thread_wait (opencl_ctx->devices_cnt, c_threads);
@@ -231,55 +231,14 @@ static int inner2_loop (hashcat_ctx_t *hashcat_ctx)
     thread_param->hashcat_ctx = hashcat_ctx;
     thread_param->tid         = device_id;
 
-    #if defined (__APPLE__)
-    size_t stackSize;
-    pthread_attr_t tattr;
-    pthread_attr_t *attrp = NULL;
-
-    if (pthread_attr_init (&tattr) != 0)
-    {
-      event_log_error (hashcat_ctx, "Failed to initialize thread attributes");
-      return -1;
-    }
-
-    if (pthread_attr_getstacksize (&tattr, &stackSize) != 0)
-    {
-      event_log_error (hashcat_ctx, "Failed to get thread stack size");
-      return -1;
-    }
-
-    if (stackSize == 0) stackSize = PTHREAD_STACK_MIN;
-    stackSize *= 2; // mitigate OSX stack overflow
-
-    if (pthread_attr_setstacksize (&tattr, stackSize) != 0)
-    {
-      event_log_error (hashcat_ctx, "Failed to set thread stack size");
-      return -1;
-    }
-
-    attrp = &tattr;
-    #endif
-
     if (user_options_extra->wordlist_mode == WL_MODE_STDIN)
     {
-      #if defined (__APPLE__)
-      hc_thread_create (c_threads[device_id], attrp, thread_calc_stdin, thread_param);
-      #else
-      hc_thread_create (c_threads[device_id], NULL, thread_calc_stdin, thread_param);
-      #endif
+      hc_thread_create (c_threads[device_id], thread_calc_stdin, thread_param);
     }
     else
     {
-      #if defined (__APPLE__)
-      hc_thread_create (c_threads[device_id], attrp, thread_calc, thread_param);
-      #else
-      hc_thread_create (c_threads[device_id], NULL, thread_calc, thread_param);
-      #endif
+      hc_thread_create (c_threads[device_id], thread_calc, thread_param);
     }
-
-    #if defined (__APPLE__)
-    if (attrp) pthread_attr_destroy (attrp);
-    #endif
   }
 
   hc_thread_wait (opencl_ctx->devices_cnt, c_threads);
@@ -709,13 +668,13 @@ static int outer_loop (hashcat_ctx_t *hashcat_ctx)
 
   if (user_options->keyspace == false && user_options->benchmark == false && user_options->stdout_flag == false && user_options->speed_only == false)
   {
-    hc_thread_create (inner_threads[inner_threads_cnt], NULL, thread_monitor, hashcat_ctx);
+    hc_thread_create (inner_threads[inner_threads_cnt], thread_monitor, hashcat_ctx);
 
     inner_threads_cnt++;
 
     if (outcheck_ctx->enabled == true)
     {
-      hc_thread_create (inner_threads[inner_threads_cnt], NULL, thread_outfile_remove, hashcat_ctx);
+      hc_thread_create (inner_threads[inner_threads_cnt], thread_outfile_remove, hashcat_ctx);
 
       inner_threads_cnt++;
     }
diff --git a/src/hashes.c b/src/hashes.c
index f7a7542e2..6bbe0fd73 100644
--- a/src/hashes.c
+++ b/src/hashes.c
@@ -183,11 +183,11 @@ int save_hash (hashcat_ctx_t *hashcat_ctx)
           fputc (separator, fp);
         }
 
-        char out_buf[HCBUFSIZ_LARGE]; // scratch buffer
+        u8 *out_buf = hashes->out_buf;
 
         out_buf[0] = 0;
 
-        ascii_digest (hashcat_ctx, out_buf, salt_pos, digest_pos);
+        ascii_digest (hashcat_ctx, (char *) out_buf, salt_pos, digest_pos);
 
         fprintf (fp, "%s" EOL, out_buf);
       }
@@ -225,17 +225,18 @@ void check_hash (hashcat_ctx_t *hashcat_ctx, hc_device_param_t *device_param, pl
 {
   debugfile_ctx_t *debugfile_ctx = hashcat_ctx->debugfile_ctx;
   loopback_ctx_t  *loopback_ctx  = hashcat_ctx->loopback_ctx;
+  hashes_t        *hashes        = hashcat_ctx->hashes;
 
   const u32 salt_pos    = plain->salt_pos;
   const u32 digest_pos  = plain->digest_pos;  // relative
 
   // hash
 
-  char out_buf[HCBUFSIZ_LARGE];
+  u8 *out_buf = hashes->out_buf;
 
   out_buf[0] = 0;
 
-  ascii_digest (hashcat_ctx, out_buf, salt_pos, digest_pos);
+  ascii_digest (hashcat_ctx, (char *) out_buf, salt_pos, digest_pos);
 
   // plain
 
@@ -264,7 +265,7 @@ void check_hash (hashcat_ctx_t *hashcat_ctx, hc_device_param_t *device_param, pl
 
   // no need for locking, we're in a mutex protected function
 
-  potfile_write_append (hashcat_ctx, out_buf, plain_ptr, plain_len);
+  potfile_write_append (hashcat_ctx, (char *) out_buf, plain_ptr, plain_len);
 
   // outfile, can be either to file or stdout
   // if an error occurs opening the file, send to stdout as fallback
@@ -274,7 +275,7 @@ void check_hash (hashcat_ctx_t *hashcat_ctx, hc_device_param_t *device_param, pl
 
   char tmp_buf[HCBUFSIZ_LARGE];
 
-  const int tmp_len = outfile_write (hashcat_ctx, out_buf, plain_ptr, plain_len, crackpos, NULL, 0, tmp_buf);
+  const int tmp_len = outfile_write (hashcat_ctx, (char *) out_buf, plain_ptr, plain_len, crackpos, NULL, 0, tmp_buf);
 
   outfile_write_close (hashcat_ctx);
 
@@ -1298,6 +1299,18 @@ int hashes_init_stage4 (hashcat_ctx_t *hashcat_ctx)
   hashes->hashes_cnt = 0;
   hashes->hashes_buf = NULL;
 
+  // starting from here, we should allocate some scratch buffer for later use
+
+  u8 *out_buf = (u8 *) hcmalloc (hashcat_ctx, HCBUFSIZ_LARGE); VERIFY_PTR (out_buf);
+
+  hashes->out_buf = out_buf;
+
+  // we need two buffers in parallel
+
+  u8 *tmp_buf = (u8 *) hcmalloc (hashcat_ctx, HCBUFSIZ_LARGE); VERIFY_PTR (tmp_buf);
+
+  hashes->tmp_buf = tmp_buf;
+
   return 0;
 }
 
@@ -1316,6 +1329,9 @@ void hashes_destroy (hashcat_ctx_t *hashcat_ctx)
 
   hcfree (hashes->hash_info);
 
+  hcfree (hashes->out_buf);
+  hcfree (hashes->tmp_buf);
+
   memset (hashes, 0, sizeof (hashes_t));
 }
 
diff --git a/src/main.c b/src/main.c
index e969798a9..d4ecc6515 100644
--- a/src/main.c
+++ b/src/main.c
@@ -170,7 +170,7 @@ static void main_outerloop_starting (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, MA
     {
       // see thread_keypress() how to access status information
 
-      hc_thread_create (hashcat_user->outer_threads[hashcat_user->outer_threads_cnt], NULL, thread_keypress, hashcat_ctx);
+      hc_thread_create (hashcat_user->outer_threads[hashcat_user->outer_threads_cnt], thread_keypress, hashcat_ctx);
 
       hashcat_user->outer_threads_cnt++;
     }
diff --git a/src/potfile.c b/src/potfile.c
index 99a3595d5..ebf1dd246 100644
--- a/src/potfile.c
+++ b/src/potfile.c
@@ -539,13 +539,15 @@ int potfile_handle_show (hashcat_ctx_t *hashcat_ctx)
 
       if (digests_shown[hashes_idx] == 0) continue;
 
-      char out_buf[HCBUFSIZ_LARGE]; // scratch buffer
+      u8 *out_buf = hashes->out_buf;
 
       out_buf[0] = 0;
 
-      ascii_digest (hashcat_ctx, out_buf, salt_idx, digest_idx);
+      ascii_digest (hashcat_ctx, (char *) out_buf, salt_idx, digest_idx);
 
-      char tmp_buf[HCBUFSIZ_LARGE]; // scratch buffer
+      u8 *tmp_buf = hashes->tmp_buf;
+
+      tmp_buf[0] = 0;
 
       hash_t *hash = &hashes_buf[hashes_idx];
 
@@ -568,7 +570,7 @@ int potfile_handle_show (hashcat_ctx_t *hashcat_ctx)
         }
       }
 
-      const int tmp_len = outfile_write (hashcat_ctx, out_buf, (unsigned char *) hash->pw_buf, hash->pw_len, 0, username, user_len, tmp_buf);
+      const int tmp_len = outfile_write (hashcat_ctx, (char *) out_buf, (u8 *) hash->pw_buf, hash->pw_len, 0, username, user_len, (char *) tmp_buf);
 
       EVENT_DATA (EVENT_POTFILE_HASH_SHOW, tmp_buf, tmp_len);
     }
@@ -600,11 +602,11 @@ int potfile_handle_left (hashcat_ctx_t *hashcat_ctx)
 
       if (digests_shown[hashes_idx] == 1) continue;
 
-      char out_buf[HCBUFSIZ_LARGE]; // scratch buffer
+      u8 *out_buf = hashes->out_buf;
 
       out_buf[0] = 0;
 
-      ascii_digest (hashcat_ctx, out_buf, salt_idx, digest_idx);
+      ascii_digest (hashcat_ctx, (char *) out_buf, salt_idx, digest_idx);
 
       hash_t *hash = &hashes_buf[hashes_idx];
 
@@ -627,9 +629,9 @@ int potfile_handle_left (hashcat_ctx_t *hashcat_ctx)
         }
       }
 
-      char tmp_buf[HCBUFSIZ_LARGE]; // scratch buffer
+      u8 *tmp_buf = hashes->tmp_buf;
 
-      const int tmp_len = outfile_write (hashcat_ctx, out_buf, NULL, 0, 0, username, user_len, tmp_buf);
+      const int tmp_len = outfile_write (hashcat_ctx, (char *) out_buf, NULL, 0, 0, username, user_len, (char *) tmp_buf);
 
       EVENT_DATA (EVENT_POTFILE_HASH_LEFT, tmp_buf, tmp_len);
     }