diff --git a/CLAUDE.md b/CLAUDE.md
index 4d53db0d..2e356aad 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -74,7 +74,7 @@ The support matrix is **auto-generated** at configure time from the `WORKLOADS`
 | `cc/d2pl/`   | — | — | ✓ | sBoMB + dBoMB |
 
 **Not built by default** ([CMakeLists.txt](CMakeLists.txt) keeps the line commented):
-- `cc/occ/` — present in tree but uses a plain Makefile, not wired into the CMake tree.
+- [cc/occ/](cc/occ/) — present in tree but uses a plain Makefile on the legacy uint64-key API, not wired into the CMake tree.
 
 `cc/si/` is a fresh implementation derived from `cc/ermia/` by stripping the SSN (Serial Safety Net) layer; the original legacy `si/` (uint64-key API) was replaced. `cc/d2pl/` deliberately doesn't support TPC-C — its deterministic locking model needs pre-declared `lock_entries_`, which the optimistic-style TPC-C templates don't provide.
 
diff --git a/occ/Makefile b/cc/occ/Makefile
similarity index 88%
rename from occ/Makefile
rename to cc/occ/Makefile
index 8eceadea..990d0fe2 100644
--- a/occ/Makefile
+++ b/cc/occ/Makefile
@@ -1,7 +1,7 @@
 PROG1 = occ.exe
 SV_FORMAT_SRCS1 := occ.cc transaction.cc util.cc result.cc
 
-REL := ../common/
+REL := ../../common/
 include $(REL)Makefile
 SV_FORMAT_ALLSRC = $(SV_FORMAT_SRCS1) $(SRCS2) $(wildcard include/*.hh)
 
@@ -35,7 +35,7 @@ CFLAGS = -c -pipe -g -O3 -std=c++17 -march=native \
 				 -DWAL=$(WAL) \
 
 INCLUDE = -I/usr/include \
-					-I../third_party/ \
+					-I../../third_party/ \
 
 LDLIBS = -lpthread -lboost_filesystem -lboost_system -lgflags -lglog
 
@@ -43,7 +43,7 @@ OBJS1 = $(SV_FORMAT_SRCS1:.cc=.o)
 
 all: $(PROG1)
 
-include ../include/MakefileForMasstreeUse
+include ../../include/MakefileForMasstreeUse
 $(PROG1) : $(OBJS1) $(MASSOBJ)
 	$(CC) -o $@ $^ $(LDFLAGS) $(LDLIBS) $(INCLUDE)
 
@@ -55,5 +55,5 @@ format:
 
 clean:
 	rm -f *~ *.o *.exe *.stackdump
-	rm -f ../common/*~ ../common/*.o ../common/*.exe ../common/*.stackdump
+	rm -f ../../common/*~ ../../common/*.o ../../common/*.exe ../../common/*.stackdump
 	rm -rf .deps
diff --git a/occ/README.md b/cc/occ/README.md
similarity index 100%
rename from occ/README.md
rename to cc/occ/README.md
diff --git a/occ/include/atomic_tool.hh b/cc/occ/include/atomic_tool.hh
similarity index 94%
rename from occ/include/atomic_tool.hh
rename to cc/occ/include/atomic_tool.hh
index 36a62ad2..85a2c9a0 100644
--- a/occ/include/atomic_tool.hh
+++ b/cc/occ/include/atomic_tool.hh
@@ -2,7 +2,7 @@
 
 #include "common.hh"
 
-#include "../../include/inline.hh"
+#include "../../../include/inline.hh"
 
 INLINE uint64_t atomicLoadGE();
 
diff --git a/occ/include/common.hh b/cc/occ/include/common.hh
similarity index 92%
rename from occ/include/common.hh
rename to cc/occ/include/common.hh
index bb95fa6f..1994482f 100644
--- a/occ/include/common.hh
+++ b/cc/occ/include/common.hh
@@ -6,9 +6,9 @@
 
 #include "tuple.hh"
 
-#include "../../include/cache_line_size.hh"
-#include "../../include/int64byte.hh"
-#include "../../include/masstree_wrapper.hh"
+#include "../../../include/cache_line_size.hh"
+#include "../../../include/int64byte.hh"
+#include "../../../include/masstree_wrapper.hh"
 
 #include "gflags/gflags.h"
 #include "glog/logging.h"
diff --git a/occ/include/log.hh b/cc/occ/include/log.hh
similarity index 100%
rename from occ/include/log.hh
rename to cc/occ/include/log.hh
diff --git a/occ/include/occ_op_element.hh b/cc/occ/include/occ_op_element.hh
similarity index 94%
rename from occ/include/occ_op_element.hh
rename to cc/occ/include/occ_op_element.hh
index 8da5c9a6..1f117dad 100644
--- a/occ/include/occ_op_element.hh
+++ b/cc/occ/include/occ_op_element.hh
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "../../include/op_element.hh"
+#include "../../../include/op_element.hh"
 
 template <typename T>
 class ReadElement : public OpElement<T> {
diff --git a/occ/include/result.hh b/cc/occ/include/result.hh
similarity index 72%
rename from occ/include/result.hh
rename to cc/occ/include/result.hh
index d6e6ad40..904684ba 100644
--- a/occ/include/result.hh
+++ b/cc/occ/include/result.hh
@@ -2,7 +2,7 @@
 
 #include <vector>
 
-#include "../../include/result.hh"
+#include "../../../include/result.hh"
 
 extern std::vector<Result> OccResult;
 
diff --git a/occ/include/transaction.hh b/cc/occ/include/transaction.hh
similarity index 93%
rename from occ/include/transaction.hh
rename to cc/occ/include/transaction.hh
index 0660e117..c6e3118f 100644
--- a/occ/include/transaction.hh
+++ b/cc/occ/include/transaction.hh
@@ -4,10 +4,10 @@
 #include <set>
 #include <vector>
 
-#include "../../include/fileio.hh"
-#include "../../include/procedure.hh"
-#include "../../include/result.hh"
-#include "../../include/string.hh"
+#include "../../../include/fileio.hh"
+#include "../../../include/procedure.hh"
+#include "../../../include/result.hh"
+#include "../../../include/string.hh"
 #include "common.hh"
 #include "log.hh"
 #include "occ_op_element.hh"
diff --git a/occ/include/tuple.hh b/cc/occ/include/tuple.hh
similarity index 75%
rename from occ/include/tuple.hh
rename to cc/occ/include/tuple.hh
index b3f37222..ae7244a1 100644
--- a/occ/include/tuple.hh
+++ b/cc/occ/include/tuple.hh
@@ -6,7 +6,7 @@
 #include <atomic>
 #include <cstdint>
 
-#include "../../include/cache_line_size.hh"
+#include "../../../include/cache_line_size.hh"
 
 class Tuple {
  public:
diff --git a/occ/include/util.hh b/cc/occ/include/util.hh
similarity index 100%
rename from occ/include/util.hh
rename to cc/occ/include/util.hh
diff --git a/occ/occ.cc b/cc/occ/occ.cc
similarity index 90%
rename from occ/occ.cc
rename to cc/occ/occ.cc
index 3d06ba2a..585fd66c 100644
--- a/occ/occ.cc
+++ b/cc/occ/occ.cc
@@ -19,18 +19,18 @@
 #include "include/transaction.hh"
 #include "include/util.hh"
 
-#include "../include/atomic_wrapper.hh"
-#include "../include/backoff.hh"
-#include "../include/cpu.hh"
-#include "../include/debug.hh"
-#include "../include/fileio.hh"
-#include "../include/masstree_wrapper.hh"
-#include "../include/random.hh"
-#include "../include/result.hh"
-#include "../include/rwlock.hh"
-#include "../include/tsc.hh"
-#include "../include/util.hh"
-#include "../include/zipf.hh"
+#include "../../include/atomic_wrapper.hh"
+#include "../../include/backoff.hh"
+#include "../../include/cpu.hh"
+#include "../../include/debug.hh"
+#include "../../include/fileio.hh"
+#include "../../include/masstree_wrapper.hh"
+#include "../../include/random.hh"
+#include "../../include/result.hh"
+#include "../../include/rwlock.hh"
+#include "../../include/tsc.hh"
+#include "../../include/util.hh"
+#include "../../include/zipf.hh"
 
 using namespace std;
 
diff --git a/occ/result.cc b/cc/occ/result.cc
similarity index 76%
rename from occ/result.cc
rename to cc/occ/result.cc
index 58f59091..c26e4712 100644
--- a/occ/result.cc
+++ b/cc/occ/result.cc
@@ -1,8 +1,8 @@
 #include "include/result.hh"
 #include "include/common.hh"
 
-#include "../include/cache_line_size.hh"
-#include "../include/result.hh"
+#include "../../include/cache_line_size.hh"
+#include "../../include/result.hh"
 
 using namespace std;
 
diff --git a/occ/transaction.cc b/cc/occ/transaction.cc
similarity index 94%
rename from occ/transaction.cc
rename to cc/occ/transaction.cc
index 36e77f52..7f550710 100644
--- a/occ/transaction.cc
+++ b/cc/occ/transaction.cc
@@ -12,12 +12,12 @@
 #include "include/log.hh"
 #include "include/transaction.hh"
 
-#include "../include/backoff.hh"
-#include "../include/debug.hh"
-#include "../include/fileio.hh"
-#include "../include/masstree_wrapper.hh"
-#include "../include/tsc.hh"
-#include "../include/util.hh"
+#include "../../include/backoff.hh"
+#include "../../include/debug.hh"
+#include "../../include/fileio.hh"
+#include "../../include/masstree_wrapper.hh"
+#include "../../include/tsc.hh"
+#include "../../include/util.hh"
 
 extern void displayDB();
 
diff --git a/occ/util.cc b/cc/occ/util.cc
similarity index 91%
rename from occ/util.cc
rename to cc/occ/util.cc
index 6430ea42..ef08e77b 100644
--- a/occ/util.cc
+++ b/cc/occ/util.cc
@@ -19,15 +19,15 @@
 #include "include/tuple.hh"
 #include "include/util.hh"
 
-#include "../include/cache_line_size.hh"
-#include "../include/config.hh"
-#include "../include/debug.hh"
-#include "../include/masstree_wrapper.hh"
-#include "../include/procedure.hh"
-#include "../include/random.hh"
-#include "../include/tsc.hh"
-#include "../include/util.hh"
-#include "../include/zipf.hh"
+#include "../../include/cache_line_size.hh"
+#include "../../include/config.hh"
+#include "../../include/debug.hh"
+#include "../../include/masstree_wrapper.hh"
+#include "../../include/procedure.hh"
+#include "../../include/random.hh"
+#include "../../include/tsc.hh"
+#include "../../include/util.hh"
+#include "../../include/zipf.hh"
 
 void chkArg() {
   displayParameter();
diff --git a/docs/protocols.md b/docs/protocols.md
index 56035171..c9c2804a 100644
--- a/docs/protocols.md
+++ b/docs/protocols.md
@@ -27,8 +27,8 @@ build).
 
 | Directory | Notes |
 |---|---|
-| `cc/occ/` (not yet moved) | K&R OCC (Kung & Robinson, 1981). Uses a plain Makefile, not wired into the CMake tree. |
+| [cc/occ](../cc/occ/) | K&R OCC (Kung & Robinson, 1981). Uses a plain Makefile (on the legacy uint64-key API), not wired into the CMake tree. |
 
-To enable, add it to the `foreach(_proto …)` loop in the top-level
-[CMakeLists.txt](../CMakeLists.txt) once it has a `ccbench_add_protocol(...)`
-entry under `cc/`.
+To enable, port `cc/occ/` to a `ccbench_add_protocol(...)` entry and add
+it to the `foreach(_proto …)` loop in the top-level
+[CMakeLists.txt](../CMakeLists.txt).