diff --git a/src/process/ntapi_tt_spawn_foreign_process.c b/src/process/ntapi_tt_spawn_foreign_process.c
index 9867b1f..03bf83f 100644
--- a/src/process/ntapi_tt_spawn_foreign_process.c
+++ b/src/process/ntapi_tt_spawn_foreign_process.c
@@ -14,6 +14,10 @@
 #include <ntapi/ntapi.h>
 #include "ntapi_impl.h"
 
+#define __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_ALLOC_SIZE    (0x50000)
+#define __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_BUFFER_SIZE   (0x30000)
+#define __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE   (0x10000)
+#define __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_IMGBUF_SIZE   (0x10000)
 
 #define NT_PROCESS_SPAWN_FLAG_DEBUG_MASK                \
 		(NT_PROCESS_SPAWN_FLAG_DEBUG_EXECUTION   \
@@ -69,7 +73,6 @@ int32_t __stdcall __ntapi_tt_spawn_foreign_process(nt_spawn_process_params * spa
 	void *				hfile;
 	uint32_t			written;
 	int32_t				envc;
-	size_t				buflen;
 	wchar16_t *			imgbuf;
 	wchar16_t *			wenv;
 	wchar16_t **			wenvp;
@@ -133,7 +136,7 @@ int32_t __stdcall __ntapi_tt_spawn_foreign_process(nt_spawn_process_params * spa
 
 	/* rtblock, rdata */
 	rtblock.addr		= 0;
-	rtblock.size		= 0x50000;
+	rtblock.size		= __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_ALLOC_SIZE;
 	rtblock.remote_addr	= 0;
 	rtblock.remote_size	= 0;
 	rtblock.flags		= 0;
@@ -154,22 +157,21 @@ int32_t __stdcall __ntapi_tt_spawn_foreign_process(nt_spawn_process_params * spa
 		envc++;
 
 	wenvp   = rtblock.addr;
-	wenvp  += 0x40000 / sizeof(*wenvp);
+	wenvp  += __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_BUFFER_SIZE / sizeof(*wenvp);
 	wenv    = (wchar16_t *)&wenvp[++envc];
 
-	buflen  = 0x10000;
-	buflen -= sizeof(*wenvp) * envc;
-
 	if ((status = __ntapi->tt_array_convert_utf8_to_utf16(
 			sparams->envp,
 			wenvp,0,wenv,
-			buflen,&(size_t){0})))
+			__SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE,
+			&(size_t){0})))
 		return __tt_spawn_return(
 			&rtblock,0,0,status);
 
 	/* imgbuf */
-	imgbuf  = (wchar16_t *)rtblock.addr;
-	imgbuf += 0x30000 / sizeof(*imgbuf);
+	imgbuf  = rtblock.addr;
+	imgbuf += __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_BUFFER_SIZE / sizeof(wchar16_t);
+	imgbuf += __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE / sizeof(wchar16_t);
 
 	/* hfile */
 	if (sparams->himage)
@@ -177,22 +179,23 @@ int32_t __stdcall __ntapi_tt_spawn_foreign_process(nt_spawn_process_params * spa
 
 	else if ((status = __ntapi_tt_open_file_utf8(
 			&hfile,hat,patharg,1,
-			imgbuf,0x2000)))
+			imgbuf,__SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_IMGBUF_SIZE)))
 		return status;
 
 	/* imgname */
 	if ((status = __ntapi->zw_query_object(
 			hfile,
 			NT_OBJECT_NAME_INFORMATION,
-			imgbuf,0x10000,&written)))
+			imgbuf,__SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE,
+			&written)))
 		return __tt_spawn_return(
 			&rtblock,0,0,status);
 
 	imgname = (nt_unicode_string *)imgbuf;
 
 	/* argv --> cmdline (utf8) */
-	ch_arg = (char *)rtblock.addr;
-	ch_cap = ch_arg + 0x10000;
+	ch_arg = rtblock.addr;
+	ch_cap = ch_arg + __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE;
 
 	for (parg=sparams->argv; *parg; parg++) {
 		for (ch=*parg, fquote=0; *ch && !fquote; ch++)
@@ -251,13 +254,13 @@ int32_t __stdcall __ntapi_tt_spawn_foreign_process(nt_spawn_process_params * spa
 	ch_arg[-1] = 0;
 
 	/* cmdline (utf8) --> cmdline (utf16) */
-	cmdline  = (wchar16_t *)rtblock.addr;
-	cmdline += (0x10000 / sizeof(wchar16_t));
+	cmdline  = rtblock.addr;
+	cmdline += __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE / sizeof(wchar16_t);
 
-	uparams.src                = (unsigned char *)rtblock.addr;
+	uparams.src                = rtblock.addr;
 	uparams.src_size_in_bytes  = 0;
 	uparams.dst                = cmdline;
-	uparams.dst_size_in_bytes  = 0x10000 - sizeof(wchar16_t);
+	uparams.dst_size_in_bytes  = __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE - sizeof(wchar16_t);
 	uparams.code_points        = 0;
 	uparams.bytes_written      = 0;
 
@@ -278,13 +281,14 @@ int32_t __stdcall __ntapi_tt_spawn_foreign_process(nt_spawn_process_params * spa
 	nt_cmd_line.buffer = cmdline;
 
 	/* nt_image */
-	nt_image.buffer  = (wchar16_t *)rtblock.addr;
-	nt_image.buffer += (0x20000 / sizeof(wchar16_t));
+	nt_image.buffer  = rtblock.addr;
+	nt_image.buffer += __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE / sizeof(wchar16_t);
+	nt_image.buffer += __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE / sizeof(wchar16_t);
 
 	uparams.src                = (unsigned char *)sparams->argv[0];
 	uparams.src_size_in_bytes  = 0;
 	uparams.dst                = nt_image.buffer;
-	uparams.dst_size_in_bytes  = 0x10000 - sizeof(wchar16_t);
+	uparams.dst_size_in_bytes  = __SPAWN_FOREIGN_PROCESS_RUNTIME_BLOCK_VECTOR_SIZE - sizeof(wchar16_t);
 	uparams.code_points        = 0;
 	uparams.bytes_written      = 0;