diff --git a/make/pre-make.r3 b/make/pre-make.r3
index 21a7aff9f0..e3d810ac77 100644
--- a/make/pre-make.r3
+++ b/make/pre-make.r3
@@ -112,6 +112,7 @@ target:   any [spec/target spec/os-target spec/configuration]
 os-base:  'win32
 product:  any [spec/product 'Core]
 configs:  unique any [spec/config copy []]
+stack-size: any [spec/stack-size 1048576] ;default 1MiB
 
 
 unless target [
diff --git a/make/rebol3.nest b/make/rebol3.nest
index bd8d918cae..24c5e8a375 100644
--- a/make/rebol3.nest
+++ b/make/rebol3.nest
@@ -16,7 +16,7 @@ include:  %src/include/
 temp:     %make/tmp/
 ;output:   %build/
 
-stack-size: 4194304
+stack-size: 4194304 ;= 4MB (4 * 1024 * 1024)
 optimize:   2
 
 version: 3.5.5
@@ -296,6 +296,7 @@ config: [ ;- this is list of configuration (optional) defines
 
 	;SERIES_LABELS ; used for special debug purposes
 	;SHOW_SIZEOFS  ; for debugging ports to some new systems
+	;SHOW_EXPAND_STACK ; will print info when stack expands
 	;NDEBUG        ; removes some asserts
 	;TEST_SCAN
 	;_DEBUG
diff --git a/make/tools/make-boot.reb b/make/tools/make-boot.reb
index 1827400dfc..5cec389c95 100644
--- a/make/tools/make-boot.reb
+++ b/make/tools/make-boot.reb
@@ -1178,6 +1178,9 @@ emit-head "Build configuration" %config.h
 
 emit {^/#ifndef REBOL_OPTIONS_H^/}
 
+if stack-size [
+	emit ajoin ["#define STACK_SIZE " stack-size lf lf]
+]
 foreach def configs [
 	emit ajoin ["#define " def lf]
 ]
diff --git a/src/core/c-do.c b/src/core/c-do.c
index ec20b84583..267bc3f2a5 100644
--- a/src/core/c-do.c
+++ b/src/core/c-do.c
@@ -105,7 +105,9 @@ static REBVAL *Func_Word(REBINT dsf)
 	}
 	Extend_Series(DS_Series, amount);
 	DS_Base = BLK_HEAD(DS_Series);
+#ifdef SHOW_EXPAND_STACK
 	Debug_Fmt(BOOT_STR(RS_STACK, 0), DSP, SERIES_REST(DS_Series));
+#endif
 }
 
 
@@ -861,7 +863,7 @@ x*/	static REBINT Do_Args_Light(REBVAL *func, REBVAL *path, REBSER *block, REBCN
 
 	//CHECK_MEMORY(1);
 	CHECK_STACK(&value);
-	if ((DSP + 20) > (REBINT)SERIES_REST(DS_Series)) Expand_Stack(STACK_MIN); //Trap0(RE_STACK_OVERFLOW);
+	if ((DSP + 200) > (REBINT)SERIES_REST(DS_Series)) Expand_Stack(STACK_MIN); //Trap0(RE_STACK_OVERFLOW); 
 	if (--Eval_Count <= 0 || Eval_Signals) Do_Signals();
 
 	value = BLK_SKIP(block, index);
diff --git a/src/include/sys-core.h b/src/include/sys-core.h
index dc3dfe41d8..cb42ffd5bb 100644
--- a/src/include/sys-core.h
+++ b/src/include/sys-core.h
@@ -39,6 +39,9 @@
 //#define MUNGWALL				// memory allocation bounds checking
 #define STACK_MIN   4000		// data stack increment size
 #define STACK_LIMIT 400000		// data stack max (6.4MB)
+#ifndef STACK_SIZE
+#define STACK_SIZE (1 * 1024 * 1024) // Default MSVS stack size is 1MiB
+#endif
 #define MIN_COMMON 10000		// min size of common buffer
 #define MAX_COMMON 100000		// max size of common buffer (shrink trigger)
 #define	MAX_NUM_LEN 64			// As many numeric digits we will accept on input
@@ -354,8 +357,9 @@ enum {
 #else
 #define CHECK_STACK(v) if ((REBUPT)(v) <= Stack_Limit) Trap_Stack();
 #endif
-#define STACK_BOUNDS (4*1024*1000) // note: need a better way to set it !!
-// Also: made somewhat smaller than linker setting to allow trapping it
+#define STACK_BOUNDS (STACK_SIZE - (24 * 1024)) // made somewhat smaller than linker setting to allow trapping it
+//NOTE: in VS Debug build the stack overflow is detected before trying to expand the data stack!
+//      So use Relase build to test the stack expansion.
 
 
 /***********************************************************************