diff --git a/bootstrap/unix-44/Out.c b/bootstrap/unix-44/Out.c
index 090b2c81..b877f0bd 100644
--- a/bootstrap/unix-44/Out.c
+++ b/bootstrap/unix-44/Out.c
@@ -359,7 +359,7 @@ void Out_DumpHeap (void)
 			Out_Hex(baddr, 1);
 			Out_Ln();
 			b = (block__4)(ADDRESS)baddr;
-			tag = (adrptr__3)(ADDRESS)b->tag;
+			tag = (adrptr__3)(ADDRESS)(b->tag - __MASK(b->tag, -2));
 			Out_String((CHAR*)"    tag:      ", 15);
 			Out_Hex(b->tag, 1);
 			if (__MASK(b->tag, -2) != 0) {
diff --git a/bootstrap/unix-48/Out.c b/bootstrap/unix-48/Out.c
index 090b2c81..b877f0bd 100644
--- a/bootstrap/unix-48/Out.c
+++ b/bootstrap/unix-48/Out.c
@@ -359,7 +359,7 @@ void Out_DumpHeap (void)
 			Out_Hex(baddr, 1);
 			Out_Ln();
 			b = (block__4)(ADDRESS)baddr;
-			tag = (adrptr__3)(ADDRESS)b->tag;
+			tag = (adrptr__3)(ADDRESS)(b->tag - __MASK(b->tag, -2));
 			Out_String((CHAR*)"    tag:      ", 15);
 			Out_Hex(b->tag, 1);
 			if (__MASK(b->tag, -2) != 0) {
diff --git a/bootstrap/unix-88/Out.c b/bootstrap/unix-88/Out.c
index d0223799..1087252f 100644
--- a/bootstrap/unix-88/Out.c
+++ b/bootstrap/unix-88/Out.c
@@ -359,7 +359,7 @@ void Out_DumpHeap (void)
 			Out_Hex(baddr, 1);
 			Out_Ln();
 			b = (block__4)(ADDRESS)baddr;
-			tag = (adrptr__3)(ADDRESS)b->tag;
+			tag = (adrptr__3)(ADDRESS)(b->tag - __MASK(b->tag, -2));
 			Out_String((CHAR*)"    tag:      ", 15);
 			Out_Hex(b->tag, 1);
 			if (__MASK(b->tag, -2) != 0) {
diff --git a/bootstrap/windows-48/Out.c b/bootstrap/windows-48/Out.c
index ef5d74e5..4c3ea533 100644
--- a/bootstrap/windows-48/Out.c
+++ b/bootstrap/windows-48/Out.c
@@ -359,7 +359,7 @@ void Out_DumpHeap (void)
 			Out_Hex(baddr, 1);
 			Out_Ln();
 			b = (block__4)(ADDRESS)baddr;
-			tag = (adrptr__3)(ADDRESS)b->tag;
+			tag = (adrptr__3)(ADDRESS)(b->tag - __MASK(b->tag, -2));
 			Out_String((CHAR*)"    tag:      ", 15);
 			Out_Hex(b->tag, 1);
 			if (__MASK(b->tag, -2) != 0) {
diff --git a/bootstrap/windows-88/Out.c b/bootstrap/windows-88/Out.c
index bbb5de28..39c1e9f9 100644
--- a/bootstrap/windows-88/Out.c
+++ b/bootstrap/windows-88/Out.c
@@ -359,7 +359,7 @@ void Out_DumpHeap (void)
 			Out_Hex(baddr, 1);
 			Out_Ln();
 			b = (block__4)(ADDRESS)baddr;
-			tag = (adrptr__3)(ADDRESS)b->tag;
+			tag = (adrptr__3)(ADDRESS)(b->tag - __MASK(b->tag, -2));
 			Out_String((CHAR*)"    tag:      ", 15);
 			Out_Hex(b->tag, 1);
 			if (__MASK(b->tag, -2) != 0) {