diff --git a/java/core/BUILD.bazel b/java/core/BUILD.bazel
index b896c426b9..57f9d61512 100644
--- a/java/core/BUILD.bazel
+++ b/java/core/BUILD.bazel
@@ -540,3 +540,72 @@ pkg_files(
     strip_prefix = strip_prefix.from_root(""),
     visibility = ["//java:__pkg__"],
 )
+
+# Genrules to expose test gencode srcjars / jars for testing compatibility of old gencode against newer runtimes.
+genrule(
+    name = "generic_test_protos_java_proto_srcjar",
+    srcs = [
+        "//java/core:java_test_protos_java_proto",
+        "//java/core:generic_test_protos_java_proto",
+        "//java/core:lite_test_protos_java_proto",
+    ],
+    outs = [
+        "java_test_protos-speed.srcjar",
+        "generic_test_protos-speed.srcjar",
+        "lite_test_protos-speed.srcjar",
+    ],
+    visibility = [
+        "//visibility:public",
+    ],
+    cmd = """
+          for location in $(locations //java/core:java_test_protos_java_proto); do
+            if [[ $$(basename $$location) == 'java_test_protos-speed-src.jar' ]]; then
+              cp $$location $(location java_test_protos-speed.srcjar);
+            fi
+          done;
+          for location in $(locations //java/core:generic_test_protos_java_proto); do
+            if [[ $$(basename $$location) == 'generic_test_protos-speed-src.jar' ]]; then
+              cp $$location $(location generic_test_protos-speed.srcjar);
+            fi
+          done;
+          for location in $(locations //java/core:lite_test_protos_java_proto); do
+            if [[ $$(basename $$location) == 'lite_test_protos-speed-src.jar' ]]; then
+              cp $$location $(location lite_test_protos-speed.srcjar);
+            fi
+          done;
+          """,
+)
+
+genrule(
+    name = "generic_test_protos_java_proto_jar",
+    srcs = [
+        "//java/core:java_test_protos_java_proto",
+        "//java/core:generic_test_protos_java_proto",
+        "//java/core:lite_test_protos_java_proto",
+    ],
+    outs = [
+        "libjava_test_protos-speed.jar",
+        "libgeneric_test_protos-speed.jar",
+        "liblite_test_protos-speed.jar",
+    ],
+    visibility = [
+        "//visibility:public",
+    ],
+    cmd = """
+          for location in $(locations //java/core:java_test_protos_java_proto); do
+            if [[ $$(basename $$location) == 'libjava_test_protos-speed.jar' ]]; then
+              cp $$location $(location libjava_test_protos-speed.jar);
+            fi
+          done;
+          for location in $(locations //java/core:generic_test_protos_java_proto); do
+            if [[ $$(basename $$location) == 'libgeneric_test_protos-speed.jar' ]]; then
+              cp $$location $(location libgeneric_test_protos-speed.jar);
+            fi
+          done;
+          for location in $(locations //java/core:lite_test_protos_java_proto); do
+            if [[ $$(basename $$location) == 'liblite_test_protos-speed.jar' ]]; then
+              cp $$location $(location liblite_test_protos-speed.jar);
+            fi
+          done;
+          """,
+)
\ No newline at end of file