diff --git a/src/gc/gc_gms.c b/src/gc/gc_gms.c
index 31245f47a5..67d17b7aa6 100644
--- a/src/gc/gc_gms.c
+++ b/src/gc/gc_gms.c
@@ -1738,7 +1738,6 @@ gc_gms_block_GC_mark(PARROT_INTERP)
     ASSERT_ARGS(gc_gms_block_GC_mark)
     MarkSweep_GC * const self = (MarkSweep_GC *)interp->gc_sys->gc_private;
     ++self->gc_mark_block_level;
-    Parrot_shared_gc_block(interp);
 }
 
 static void
@@ -1746,10 +1745,8 @@ gc_gms_unblock_GC_mark(PARROT_INTERP)
 {
     ASSERT_ARGS(gc_gms_unblock_GC_mark)
     MarkSweep_GC * const self = (MarkSweep_GC *)interp->gc_sys->gc_private;
-    if (self->gc_mark_block_level) {
+    if (self->gc_mark_block_level)
         --self->gc_mark_block_level;
-        Parrot_shared_gc_unblock(interp);
-    }
 }
 
 static void
diff --git a/src/gc/gc_ms.c b/src/gc/gc_ms.c
index d821323e45..d84f1037d4 100644
--- a/src/gc/gc_ms.c
+++ b/src/gc/gc_ms.c
@@ -1739,7 +1739,6 @@ gc_ms_block_GC_mark(PARROT_INTERP)
     ASSERT_ARGS(gc_ms_block_GC_mark)
     Memory_Pools * const mem_pools = (Memory_Pools *)interp->gc_sys->gc_private;
     ++mem_pools->gc_mark_block_level;
-    Parrot_shared_gc_block(interp);
 }
 
 static void
@@ -1747,10 +1746,8 @@ gc_ms_unblock_GC_mark(PARROT_INTERP)
 {
     ASSERT_ARGS(gc_ms_unblock_GC_mark)
     Memory_Pools * const mem_pools = (Memory_Pools *)interp->gc_sys->gc_private;
-    if (mem_pools->gc_mark_block_level) {
+    if (mem_pools->gc_mark_block_level)
         --mem_pools->gc_mark_block_level;
-        Parrot_shared_gc_unblock(interp);
-    }
 }
 
 static void
diff --git a/src/gc/gc_ms2.c b/src/gc/gc_ms2.c
index 18366e48e8..def128077e 100644
--- a/src/gc/gc_ms2.c
+++ b/src/gc/gc_ms2.c
@@ -1311,7 +1311,6 @@ gc_ms2_block_GC_mark(PARROT_INTERP)
     ASSERT_ARGS(gc_ms2_block_GC_mark)
     MarkSweep_GC * const self = (MarkSweep_GC *)interp->gc_sys->gc_private;
     ++self->gc_mark_block_level;
-    Parrot_shared_gc_block(interp);
 }
 
 
@@ -1320,10 +1319,8 @@ gc_ms2_unblock_GC_mark(PARROT_INTERP)
 {
     ASSERT_ARGS(gc_ms2_unblock_GC_mark)
     MarkSweep_GC * const self = (MarkSweep_GC *)interp->gc_sys->gc_private;
-    if (self->gc_mark_block_level) {
+    if (self->gc_mark_block_level)
         --self->gc_mark_block_level;
-        Parrot_shared_gc_unblock(interp);
-    }
 }