diff --git a/t/Makefile.am b/t/Makefile.am
index a12320a4..4e6eadb5 100644
--- a/t/Makefile.am
+++ b/t/Makefile.am
@@ -13,7 +13,7 @@ LDFLAGS_COMMON=-L$(abs_builddir)/../lib  -L$(libdir)
 ## for more information.
 LIBADD_COMMON = ../lib/libhawk.la $(LIBM)
 
-check_SCRIPTS = h-001.hawk h-002.hawk h-003.hawk h-009.hawk
+check_SCRIPTS = h-001.hawk h-002.hawk h-003.hawk h-004.hawk h-009.hawk
 ##noinst_SCRIPTS = $(check_SCRIPTS)
 EXTRA_DIST = $(check_SCRIPTS) tap.inc \
 	journal-toc.hawk journal-toc.in journal-toc.out journal-toc-html.out \
diff --git a/t/Makefile.in b/t/Makefile.in
index 9f7c7d0c..8b572318 100644
--- a/t/Makefile.in
+++ b/t/Makefile.in
@@ -578,7 +578,7 @@ CPPFLAGS_COMMON = \
 CFLAGS_COMMON = 
 LDFLAGS_COMMON = -L$(abs_builddir)/../lib  -L$(libdir)
 LIBADD_COMMON = ../lib/libhawk.la $(LIBM)
-check_SCRIPTS = h-001.hawk h-002.hawk h-003.hawk h-009.hawk
+check_SCRIPTS = h-001.hawk h-002.hawk h-003.hawk h-004.hawk h-009.hawk
 EXTRA_DIST = $(check_SCRIPTS) tap.inc \
 	journal-toc.hawk journal-toc.in journal-toc.out journal-toc-html.out \
 	bibtex-to-html.hawk bibtex-to-html.out
diff --git a/t/bibtex-to-html.hawk b/t/bibtex-to-html.hawk
index 79394f34..d354c01f 100644
--- a/t/bibtex-to-html.hawk
+++ b/t/bibtex-to-html.hawk
@@ -420,7 +420,7 @@ function do_cite(s, k,n,labels,t)
 function do_line( n,name,s)
 {
     s = protect_SGML_characters($0)
-    
+
     if (match(s,STRING_PATTERN)) # remember name from @String{name = "value"}
     {
 	name = substr(s,RSTART + STRING_OFFSET,RLENGTH - STRING_OFFSET)
@@ -520,7 +520,7 @@ function protect_SGML_characters(s)
     gsub(/</,"\\&lt;",s)
     gsub(/>/,"\\&gt;",s)
 
-    ## [24-May-2016] with the change from HTML 3.2 to 4.0, we can use &quot; again!	
+    ## [24-May-2016] with the change from HTML 3.2 to 4.0, we can use &quot; again!
     ## gsub(/\"/,"\\&#34;",s)	# this was &quot; in earlier HTML
 				# versions, including the HTML 3.2
 				# draft, but was stupidly eliminated in
diff --git a/t/h-001.hawk b/t/h-001.hawk
index 0cf82a72..fbc88a97 100644
--- a/t/h-001.hawk
+++ b/t/h-001.hawk
@@ -136,7 +136,7 @@ function main()
 
 		x = 20;
 		y = 90;
-		r = call_by_ref_1(x, y, z);	
+		r = call_by_ref_1(x, y, z);
 		tap_ensure (r, 1800, @SCRIPTNAME, @SCRIPTLINE);
 		tap_ensure (x, 20, @SCRIPTNAME, @SCRIPTLINE);
 		tap_ensure (y, 90, @SCRIPTNAME, @SCRIPTLINE);
@@ -179,7 +179,7 @@ function main()
 	{
 		@local a;
 		a[1] = hawk::array();
-		a[1][2]=20; 
+		a[1][2]=20;
 		tap_ensure (a[1][2], 20, @SCRIPTNAME, @SCRIPTLINE);
 		a[1][2]++;
 		tap_ensure (a[1][2], 21, @SCRIPTNAME, @SCRIPTLINE);
@@ -217,22 +217,22 @@ function main()
 	{
 		@local a, i;
 
-		a = hawk::array(); 
+		a = hawk::array();
 		tap_ensure (length(a), 0, @SCRIPTNAME, @SCRIPTLINE);
-		
-		for (i = 0; i < 10; i++) a[i*i]=i; 
+
+		for (i = 0; i < 10; i++) a[i*i]=i;
 		tap_ensure (length(a), 10, @SCRIPTNAME, @SCRIPTLINE);
 
 		delete a[0];
 		tap_ensure (length(a), 9, @SCRIPTNAME, @SCRIPTLINE);
 
-		delete a[81]; 
+		delete a[81];
 		tap_ensure (length(a), 8, @SCRIPTNAME, @SCRIPTLINE);
 
-		delete a[36]; 
+		delete a[36];
 		tap_ensure (length(a), 7, @SCRIPTNAME, @SCRIPTLINE);
 
-		for (i = 0; i < 10; i++) delete a[i*i]; 
+		for (i = 0; i < 10; i++) delete a[i*i];
 		tap_ensure (length(a), 0, @SCRIPTNAME, @SCRIPTLINE);
 
 		delete a;
diff --git a/t/h-003.hawk b/t/h-003.hawk
index 1741ad32..c1816e0e 100644
--- a/t/h-003.hawk
+++ b/t/h-003.hawk
@@ -6,7 +6,7 @@
 function are_files_identical(a, b)
 {
 	@local f1, f2, x, y, diff;
-	
+
 	f1 = sys::open(a, sys::O_RDONLY);
 	if (f1 <= -1)
 	{
@@ -25,7 +25,7 @@ function are_files_identical(a, b)
 	diff = 0;
 	while (sys::read(f1, x, 1) > 0)
 	{
-		if (sys::read(f2, y, 1) <= 0 || x !== y) 
+		if (sys::read(f2, y, 1) <= 0 || x !== y)
 		{
 			diff = 1;
 			break;
@@ -58,12 +58,12 @@ function run_test (x, more_opts, in_name, set_out_name, out_name)
 	else
 	{
 		cmd=sprintf("%s %s -f %s/%s.hawk --modlibdirs=%s %s > %s", ARGV[0], more_opts, TDIR, x, hawk::modlibdirs(), inf, outf);
-	}	
+	}
 ##print cmd;
 	system (cmd);
-		
+
 	same = are_files_identical(expf, outf);
-	if (same <= 0) 
+	if (same <= 0)
 	{
 		## don't delete the output file for review.
 		tap_fail (sprintf("%s[%d] %s - %s and %s differ", @SCRIPTNAME, @SCRIPTLINE, x, expf, outf));
diff --git a/t/h-004.hawk b/t/h-004.hawk
new file mode 100644
index 00000000..39f05edf
--- /dev/null
+++ b/t/h-004.hawk
@@ -0,0 +1,37 @@
+@pragma entry main
+@pragma implicit off
+
+@include "tap.inc";
+
+
+function run_gc_test ()
+{
+	@local i, a, b, ts, pr, cpr;
+
+	tap_ensure (hawk::GC_NUM_GENS, 3, @SCRIPTNAME, @SCRIPTLINE);
+	hawk::gc_set_threshold(0, 30);
+	ts = hawk::gc_get_threshold(0);
+	tap_ensure (ts, 30, @SCRIPTNAME, @SCRIPTLINE);
+
+	pr = hawk::gc_get_pressure(0);
+	for (i = 0; i < 50; i++)
+	{
+		a[1] = 999; ## there is only 1 allocation that's concerting GC in the current implementation
+		b = a;
+		b = @nil;
+		a = @nil;
+
+		cpr =  hawk::gc_get_pressure(0);
+		if (pr + i + 1 <= ts)
+			tap_ensure (cpr, pr + i + 1, @SCRIPTNAME, @SCRIPTLINE);
+		else ## gc kicks in when the pressure reaches the threshold, the pressure drops...
+			tap_ensure (cpr, (pr + i + 1) - ts, @SCRIPTNAME, @SCRIPTLINE);
+	}
+}
+
+function main()
+{
+	run_gc_test();
+	tap_end ();
+}
+