diff --git a/src/gc.c b/src/gc.c
index 99e28aa..a2f4f75 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -43,7 +43,7 @@ gc_allocator(void *opaque, void *oldptr, size_t oldsize, size_t newsize)
     struct gc *gc = opaque;
 
     void *out = ALLOCATOR_CALL(gc->base_allocator, oldptr, oldsize, newsize);
-    if (newsize != 0 && out == NULL) {
+    if (newsize != 0 && out == NULL && !gc->is_collecting) {
         // We're out of memory! Try to get out of this situation by doing a full
         // GC run.
         apfl_gc_full(gc);
@@ -87,6 +87,7 @@ apfl_gc_init(struct gc *gc, struct apfl_allocator allocator, gc_roots_getter roo
         .cap = 0,
     };
     gc->tmproot_for_adding = NULL;
+    gc->is_collecting = false;
 }
 
 static struct gc_block *
@@ -373,12 +374,17 @@ sweep(struct gc *gc)
 void
 apfl_gc_full(struct gc *gc)
 {
+    assert(!gc->is_collecting);
+    gc->is_collecting = true;
+
     mark_roots(gc);
     apfl_gc_debug_dump_graph(gc, stderr);
     trace_while_having_grey(gc);
     apfl_gc_debug_dump_graph(gc, stderr);
     sweep(gc);
     apfl_gc_debug_dump_graph(gc, stderr);
+
+    gc->is_collecting = false;
 }
 
 static const char *
diff --git a/src/gc.h b/src/gc.h
index af1d90c..07bf016 100644
--- a/src/gc.h
+++ b/src/gc.h
@@ -50,6 +50,8 @@ struct gc {
     void *roots_getter_opaque;
     struct gc_tmproots tmproots;
     struct gc_object *tmproot_for_adding;
+
+    bool is_collecting;
 };