diff --git a/mk/rt.mk b/mk/rt.mk
index c460e716e71..5e5fd8dc986 100644
--- a/mk/rt.mk
+++ b/mk/rt.mk
@@ -27,6 +27,7 @@ RUNTIME_CS := rt/sync/timer.cpp \
               rt/rust_obstack.cpp \
               rt/rust_gc.cpp \
               rt/rust_abi.cpp \
+              rt/rust_cc.cpp \
               rt/memory_region.cpp \
               rt/test/rust_test_harness.cpp \
               rt/test/rust_test_runtime.cpp \
diff --git a/src/rt/rust_cc.cpp b/src/rt/rust_cc.cpp
new file mode 100644
index 00000000000..8129f60fc7c
--- /dev/null
+++ b/src/rt/rust_cc.cpp
@@ -0,0 +1,57 @@
+// Rust cycle collector. Temporary, but will probably stick around for some
+// time until LLVM's GC infrastructure is more mature.
+
+#include <cstdio>
+#include <cstdlib>
+#include <map>
+#include <vector>
+#include "rust_gc.h"
+#include "rust_internal.h"
+#include "rust_shape.h"
+#include "rust_task.h"
+
+#undef DPRINT
+#define DPRINT(fmt,...)     fprintf(stderr, fmt, ##__VA_ARGS__)
+
+namespace cc {
+
+void
+do_cc(rust_task *task) {
+    std::map<void *,type_desc *>::iterator begin(task->local_allocs.begin());
+    std::map<void *,type_desc *>::iterator end(task->local_allocs.end());
+    while (begin != end) {
+        void *p = begin->first;
+        type_desc *tydesc = begin->second;
+
+        DPRINT("marking allocation: %p, tydesc=%p\n", p, tydesc);
+
+        // Prevents warnings for now
+        (void)p;
+        (void)tydesc;
+#if 0
+        shape::arena arena;
+        shape::type_param *params =
+            shape::type_param::from_tydesc(tydesc, arena);
+        mark mark(task, true, tydesc->shape, params, tydesc->shape_tables, p);
+        mark.walk();
+#endif
+
+        ++begin;
+    }
+}
+
+void
+maybe_cc(rust_task *task) {
+    // FIXME: We ought to lock this.
+    static int zeal = -1;
+    if (zeal == -1) {
+        char *ev = getenv("RUST_CC_ZEAL");
+        zeal = ev && ev[0] != '\0' && ev[0] != '0';
+    }
+
+    if (zeal)
+        do_cc(task);
+}
+
+}   // end namespace cc
+
diff --git a/src/rt/rust_cc.h b/src/rt/rust_cc.h
new file mode 100644
index 00000000000..991e69d5c31
--- /dev/null
+++ b/src/rt/rust_cc.h
@@ -0,0 +1,17 @@
+// Rust cycle collector. Temporary, but will probably stick around for some
+// time until LLVM's GC infrastructure is more mature.
+
+#ifndef RUST_CC_H
+#define RUST_CC_H
+
+struct rust_task;
+
+namespace cc {
+
+void do_cc(rust_task *task);
+void maybe_cc(rust_task *task);
+
+}   // end namespace cc
+
+#endif
+
diff --git a/src/rt/rust_upcall.cpp b/src/rt/rust_upcall.cpp
index 5fabb5cd1ab..863e22052e7 100644
--- a/src/rt/rust_upcall.cpp
+++ b/src/rt/rust_upcall.cpp
@@ -1,3 +1,4 @@
+#include "rust_cc.h"
 #include "rust_gc.h"
 #include "rust_internal.h"
 #include "rust_unwind.h"
@@ -61,6 +62,7 @@ upcall_malloc(rust_task *task, size_t nbytes, type_desc *td) {
         nbytes, td);
 
     gc::maybe_gc(task);
+    cc::maybe_cc(task);
 
     // TODO: Maybe use dladdr here to find a more useful name for the
     // type_desc.