diff --git a/Examples/bash/manifest.template b/Examples/bash/manifest.template
index 83c0f7f2..36f628cf 100644
--- a/Examples/bash/manifest.template
+++ b/Examples/bash/manifest.template
@@ -81,3 +81,5 @@ $(TRUSTED_LIBS)
 $(TRUSTED_CHILDREN)
 
 sgx.allowed_files.scripts = file:scripts
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/busybox/busybox.manifest.template b/Examples/busybox/busybox.manifest.template
index b0e4c235..75d2908e 100644
--- a/Examples/busybox/busybox.manifest.template
+++ b/Examples/busybox/busybox.manifest.template
@@ -140,3 +140,4 @@ sgx.allowed_files.passwd    = file:/etc/passwd
 # glibc-based host systems.
 sgx.allowed_files.localtime = file:/etc/localtime
 
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/capnproto/addressbook.manifest.template b/Examples/capnproto/addressbook.manifest.template
index 1f884535..3c1accaf 100644
--- a/Examples/capnproto/addressbook.manifest.template
+++ b/Examples/capnproto/addressbook.manifest.template
@@ -54,3 +54,5 @@ sgx.trusted_files.libc = file:$(GRAPHENEDIR)/Runtime/libc.so.6
 sgx.trusted_files.libm = file:$(GRAPHENEDIR)/Runtime/libm.so.6
 sgx.trusted_files.libpthread = file:$(GRAPHENEDIR)/Runtime/libpthread.so.0
 $(TRUSTEDLIBS)
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/curl/curl.manifest.template b/Examples/curl/curl.manifest.template
index 6dfd9178..d6ba8711 100644
--- a/Examples/curl/curl.manifest.template
+++ b/Examples/curl/curl.manifest.template
@@ -77,3 +77,5 @@ sgx.allowed_files.hosts      = file:/etc/hosts
 sgx.allowed_files.group      = file:/etc/group
 sgx.allowed_files.passwd     = file:/etc/passwd
 sgx.allowed_files.gaiconf    = file:/etc/gai.conf
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/nodejs/nodejs.manifest.template b/Examples/nodejs/nodejs.manifest.template
index 30e777ee..63aa0b04 100644
--- a/Examples/nodejs/nodejs.manifest.template
+++ b/Examples/nodejs/nodejs.manifest.template
@@ -58,3 +58,5 @@ $(NODEJS_TRUSTED_LIBS)
 
 # JavaScript (trusted)
 sgx.trusted_files.javascript = file:helloworld.js
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/python-scipy-insecure/python.manifest.template b/Examples/python-scipy-insecure/python.manifest.template
index b5cf56e9..e7a52f19 100644
--- a/Examples/python-scipy-insecure/python.manifest.template
+++ b/Examples/python-scipy-insecure/python.manifest.template
@@ -109,3 +109,5 @@ sgx.allowed_files.tmp = file:/tmp
 sgx.allowed_files.etc = file:/etc
 sgx.allowed_files.pyhome = file:$(PYTHONHOME)
 sgx.allowed_files.pydisthome = file:$(PYTHONDISTHOME)
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/python-simple/python.manifest.template b/Examples/python-simple/python.manifest.template
index 61e95b5e..c2d15fb8 100644
--- a/Examples/python-simple/python.manifest.template
+++ b/Examples/python-simple/python.manifest.template
@@ -266,3 +266,5 @@ sgx.allowed_files.passwd    = file:/etc/passwd
 sgx.allowed_files.gaiconf   = file:/etc/gai.conf
 sgx.allowed_files.hostconf  = file:/etc/host.conf
 sgx.allowed_files.resolv    = file:/etc/resolv.conf
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/r/R.manifest.template b/Examples/r/R.manifest.template
index 244c4b55..c83e0428 100644
--- a/Examples/r/R.manifest.template
+++ b/Examples/r/R.manifest.template
@@ -96,3 +96,5 @@ sgx.allowed_files.r_lib = file:$(R_HOME)/library
 # Allow creating child enclaves for sh
 sgx.trusted_files.sh = file:/bin/sh
 sgx.trusted_children.sh = file:sh.sig
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/r/sh.manifest.template b/Examples/r/sh.manifest.template
index 4fa0e321..80db9c53 100644
--- a/Examples/r/sh.manifest.template
+++ b/Examples/r/sh.manifest.template
@@ -42,3 +42,5 @@ sgx.thread_num = 2
 # SGX trusted libraries
 sgx.trusted_files.ld = file:$(GRAPHENEDIR)/Runtime/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:$(GRAPHENEDIR)/Runtime/libc.so.6
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/ra-tls-mbedtls/server.manifest.template b/Examples/ra-tls-mbedtls/server.manifest.template
index ab8837c0..a86c44b3 100644
--- a/Examples/ra-tls-mbedtls/server.manifest.template
+++ b/Examples/ra-tls-mbedtls/server.manifest.template
@@ -53,3 +53,5 @@ sgx.allowed_files.hosts     = file:/etc/hosts
 sgx.allowed_files.group     = file:/etc/group
 sgx.allowed_files.passwd    = file:/etc/passwd
 sgx.allowed_files.gaiconf   = file:/etc/gai.conf
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/ra-tls-secret-prov/secret_prov_client.manifest.template b/Examples/ra-tls-secret-prov/secret_prov_client.manifest.template
index 50b12e30..d271c4dc 100644
--- a/Examples/ra-tls-secret-prov/secret_prov_client.manifest.template
+++ b/Examples/ra-tls-secret-prov/secret_prov_client.manifest.template
@@ -60,3 +60,5 @@ sgx.allowed_files.group     = file:/etc/group
 sgx.allowed_files.passwd    = file:/etc/passwd
 sgx.allowed_files.gaiconf   = file:/etc/gai.conf
 sgx.allowed_files.resolv    = file:/etc/resolv.conf
+
+sgx.zero_heap_on_demand = 1
diff --git a/Examples/ra-tls-secret-prov/secret_prov_min_client.manifest.template b/Examples/ra-tls-secret-prov/secret_prov_min_client.manifest.template
index 39b7124b..43179002 100644
--- a/Examples/ra-tls-secret-prov/secret_prov_min_client.manifest.template
+++ b/Examples/ra-tls-secret-prov/secret_prov_min_client.manifest.template
@@ -67,3 +67,5 @@ sgx.allowed_files.group     = file:/etc/group
 sgx.allowed_files.passwd    = file:/etc/passwd
 sgx.allowed_files.gaiconf   = file:/etc/gai.conf
 sgx.allowed_files.resolv    = file:/etc/resolv.conf
+
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/fs/manifest.template b/LibOS/shim/test/fs/manifest.template
index da24ef81..e9384a66 100644
--- a/LibOS/shim/test/fs/manifest.template
+++ b/LibOS/shim/test/fs/manifest.template
@@ -36,3 +36,5 @@ sgx.allowed_files.tmp_dir = file:tmp/
 sgx.protected_files_key = ffeeddccbbaa99887766554433221100
 sgx.protected_files.input = file:tmp/pf_input
 sgx.protected_files.output = file:tmp/pf_output
+
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/ltp/manifest.template b/LibOS/shim/test/ltp/manifest.template
index 19115bf4..ff72d792 100644
--- a/LibOS/shim/test/ltp/manifest.template
+++ b/LibOS/shim/test/ltp/manifest.template
@@ -40,3 +40,5 @@ sgx.trusted_files.librt = file:$(LIBCDIR)/librt.so.1
 sgx.trusted_files.libstdbuf = file:/usr/$(ARCH_LIBDIR)/coreutils/libstdbuf.so
 
 sgx.allowed_files.tmp = file:/tmp
+
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/argv_from_file.manifest.template b/LibOS/shim/test/regression/argv_from_file.manifest.template
index 213d7de7..2c8c2801 100644
--- a/LibOS/shim/test/regression/argv_from_file.manifest.template
+++ b/LibOS/shim/test/regression/argv_from_file.manifest.template
@@ -17,3 +17,4 @@ sgx.trusted_files.ld = file:../../../../Runtime/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/attestation.manifest.template b/LibOS/shim/test/regression/attestation.manifest.template
index 03bc30b6..298b9afd 100644
--- a/LibOS/shim/test/regression/attestation.manifest.template
+++ b/LibOS/shim/test/regression/attestation.manifest.template
@@ -22,3 +22,4 @@ sgx.trusted_files.libm = file:$(LIBCDIR)/libm.so.6
 sgx.remote_attestation = 1
 sgx.ra_client_spid = $(RA_CLIENT_SPID)
 sgx.ra_client_linkable = $(RA_CLIENT_LINKABLE)
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/echo.manifest.template b/LibOS/shim/test/regression/echo.manifest.template
index e36fe7ef..58e2840b 100644
--- a/LibOS/shim/test/regression/echo.manifest.template
+++ b/LibOS/shim/test/regression/echo.manifest.template
@@ -29,3 +29,4 @@ sgx.trusted_files.ld = file:../../../../Runtime/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/env_from_file.manifest.template b/LibOS/shim/test/regression/env_from_file.manifest.template
index 6f0feeb5..13f78d7a 100644
--- a/LibOS/shim/test/regression/env_from_file.manifest.template
+++ b/LibOS/shim/test/regression/env_from_file.manifest.template
@@ -17,3 +17,4 @@ sgx.trusted_files.ld = file:../../../../Runtime/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/env_from_host.manifest.template b/LibOS/shim/test/regression/env_from_host.manifest.template
index dbf0be71..89b6be58 100644
--- a/LibOS/shim/test/regression/env_from_host.manifest.template
+++ b/LibOS/shim/test/regression/env_from_host.manifest.template
@@ -15,3 +15,4 @@ sgx.trusted_files.ld = file:../../../../Runtime/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/eventfd.manifest.template b/LibOS/shim/test/regression/eventfd.manifest.template
index 7778ef59..11cdf5b1 100644
--- a/LibOS/shim/test/regression/eventfd.manifest.template
+++ b/LibOS/shim/test/regression/eventfd.manifest.template
@@ -17,3 +17,4 @@ sgx.trusted_files.libm = file:../../../../Runtime/libm.so.6
 sgx.trusted_files.libpthread = file:../../../../Runtime/libpthread.so.0
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/exec_victim.manifest.template b/LibOS/shim/test/regression/exec_victim.manifest.template
index 09102144..892c713b 100644
--- a/LibOS/shim/test/regression/exec_victim.manifest.template
+++ b/LibOS/shim/test/regression/exec_victim.manifest.template
@@ -18,3 +18,4 @@ sgx.trusted_files.ld = file:../../../../Runtime/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/exit_group.manifest.template b/LibOS/shim/test/regression/exit_group.manifest.template
index a807d1c5..33c80d1e 100644
--- a/LibOS/shim/test/regression/exit_group.manifest.template
+++ b/LibOS/shim/test/regression/exit_group.manifest.template
@@ -16,3 +16,4 @@ sgx.trusted_files.libpthread = file:../../../../Runtime/libpthread.so.0
 sgx.thread_num = 7
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/file_check_policy_allow_all_but_log.manifest.template b/LibOS/shim/test/regression/file_check_policy_allow_all_but_log.manifest.template
index 838d36c0..de9f8582 100644
--- a/LibOS/shim/test/regression/file_check_policy_allow_all_but_log.manifest.template
+++ b/LibOS/shim/test/regression/file_check_policy_allow_all_but_log.manifest.template
@@ -17,3 +17,4 @@ sgx.trusted_files.libc = file:$(LIBCDIR)/libc.so.6
 sgx.trusted_files.test = file:trusted_testfile
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/file_check_policy_strict.manifest.template b/LibOS/shim/test/regression/file_check_policy_strict.manifest.template
index ca7d6252..51726d92 100644
--- a/LibOS/shim/test/regression/file_check_policy_strict.manifest.template
+++ b/LibOS/shim/test/regression/file_check_policy_strict.manifest.template
@@ -17,3 +17,4 @@ sgx.trusted_files.libc = file:$(LIBCDIR)/libc.so.6
 sgx.trusted_files.test = file:trusted_testfile
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/futex_bitset.manifest.template b/LibOS/shim/test/regression/futex_bitset.manifest.template
index 212df075..e620c1a6 100644
--- a/LibOS/shim/test/regression/futex_bitset.manifest.template
+++ b/LibOS/shim/test/regression/futex_bitset.manifest.template
@@ -23,3 +23,4 @@ sgx.trusted_files.libpthread = file:../../../../Runtime/libpthread.so.0
 sgx.thread_num = 16
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/futex_requeue.manifest.template b/LibOS/shim/test/regression/futex_requeue.manifest.template
index fda43235..a04870ac 100644
--- a/LibOS/shim/test/regression/futex_requeue.manifest.template
+++ b/LibOS/shim/test/regression/futex_requeue.manifest.template
@@ -18,3 +18,4 @@ sgx.trusted_files.libpthread = file:../../../../Runtime/libpthread.so.0
 sgx.thread_num = 16
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/futex_wake_op.manifest.template b/LibOS/shim/test/regression/futex_wake_op.manifest.template
index fa484c97..29fa8b48 100644
--- a/LibOS/shim/test/regression/futex_wake_op.manifest.template
+++ b/LibOS/shim/test/regression/futex_wake_op.manifest.template
@@ -18,3 +18,4 @@ sgx.trusted_files.libpthread = file:../../../../Runtime/libpthread.so.0
 sgx.thread_num = 16
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/getdents.manifest.template b/LibOS/shim/test/regression/getdents.manifest.template
index b65000da..d6cb4b9f 100644
--- a/LibOS/shim/test/regression/getdents.manifest.template
+++ b/LibOS/shim/test/regression/getdents.manifest.template
@@ -13,3 +13,4 @@ sgx.trusted_files.libc = file:$(LIBCDIR)/libc.so.6
 sgx.allowed_files.test = file:root
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/host_root_fs.manifest.template b/LibOS/shim/test/regression/host_root_fs.manifest.template
index d13d2540..a2dba6f0 100644
--- a/LibOS/shim/test/regression/host_root_fs.manifest.template
+++ b/LibOS/shim/test/regression/host_root_fs.manifest.template
@@ -17,3 +17,4 @@ sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 sgx.trusted_files.libdl = file:../../../../Runtime/libdl.so.2
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/init_fail.manifest.template b/LibOS/shim/test/regression/init_fail.manifest.template
index e9f96d11..bc6a5c3c 100644
--- a/LibOS/shim/test/regression/init_fail.manifest.template
+++ b/LibOS/shim/test/regression/init_fail.manifest.template
@@ -16,3 +16,4 @@ sgx.trusted_files.ld = file:$(LIBCDIR)/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:$(LIBCDIR)/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/large_mmap.manifest.template b/LibOS/shim/test/regression/large_mmap.manifest.template
index 59126fa7..f3f3b1c7 100644
--- a/LibOS/shim/test/regression/large_mmap.manifest.template
+++ b/LibOS/shim/test/regression/large_mmap.manifest.template
@@ -20,3 +20,4 @@ sgx.allowed_files.testfile = file:testfile
 sgx.enclave_size = 8G
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/manifest.template b/LibOS/shim/test/regression/manifest.template
index 563a3909..fa32fb25 100644
--- a/LibOS/shim/test/regression/manifest.template
+++ b/LibOS/shim/test/regression/manifest.template
@@ -46,3 +46,5 @@ sgx.static_address = 1
 
 sgx.trusted_files.sh = file:/bin/sh
 sgx.trusted_children.sh = file:sh.sig
+
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/mmap_file.manifest.template b/LibOS/shim/test/regression/mmap_file.manifest.template
index cdc9d580..3434ecc1 100644
--- a/LibOS/shim/test/regression/mmap_file.manifest.template
+++ b/LibOS/shim/test/regression/mmap_file.manifest.template
@@ -23,3 +23,4 @@ sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 sgx.allowed_files.testfile = file:testfile
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/multi_pthread.manifest.template b/LibOS/shim/test/regression/multi_pthread.manifest.template
index aff63c0f..e047790a 100644
--- a/LibOS/shim/test/regression/multi_pthread.manifest.template
+++ b/LibOS/shim/test/regression/multi_pthread.manifest.template
@@ -17,3 +17,4 @@ sgx.thread_num = 8
 
 sgx.static_address = 1
 sgx.enable_stats = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/multi_pthread_exitless.manifest.template b/LibOS/shim/test/regression/multi_pthread_exitless.manifest.template
index 6f38fb87..cc1e1f73 100644
--- a/LibOS/shim/test/regression/multi_pthread_exitless.manifest.template
+++ b/LibOS/shim/test/regression/multi_pthread_exitless.manifest.template
@@ -20,3 +20,4 @@ sgx.rpc_thread_num = 8
 
 sgx.static_address = 1
 sgx.enable_stats = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/openmp.manifest.template b/LibOS/shim/test/regression/openmp.manifest.template
index f3dae162..12065062 100644
--- a/LibOS/shim/test/regression/openmp.manifest.template
+++ b/LibOS/shim/test/regression/openmp.manifest.template
@@ -25,3 +25,4 @@ sgx.trusted_files.libdl = file:../../../../Runtime/libdl.so.2
 sgx.trusted_files.libgomp = file:/usr$(ARCH_LIBDIR)/libgomp.so.1
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/proc_path.manifest.template b/LibOS/shim/test/regression/proc_path.manifest.template
index 29fb6fa0..07a04e8c 100644
--- a/LibOS/shim/test/regression/proc_path.manifest.template
+++ b/LibOS/shim/test/regression/proc_path.manifest.template
@@ -17,3 +17,4 @@ sgx.trusted_files.ld = file:../../../../Runtime/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:../../../../Runtime/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/sh.manifest.template b/LibOS/shim/test/regression/sh.manifest.template
index 47d9d712..4fd4a4e1 100644
--- a/LibOS/shim/test/regression/sh.manifest.template
+++ b/LibOS/shim/test/regression/sh.manifest.template
@@ -32,3 +32,4 @@ sgx.trusted_files.echo = file:/bin/echo
 sgx.trusted_children.echo = file:echo.sig
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/LibOS/shim/test/regression/shared_object.manifest.template b/LibOS/shim/test/regression/shared_object.manifest.template
index 6a16f5ad..fa7a1cbe 100644
--- a/LibOS/shim/test/regression/shared_object.manifest.template
+++ b/LibOS/shim/test/regression/shared_object.manifest.template
@@ -11,3 +11,4 @@ sgx.trusted_files.ld = file:$(LIBCDIR)/ld-linux-x86-64.so.2
 sgx.trusted_files.libc = file:$(LIBCDIR)/libc.so.6
 
 sgx.static_address = 1
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/AvxDisable.manifest.template b/Pal/regression/AvxDisable.manifest.template
index 8daf2ece..df2ea8bf 100644
--- a/Pal/regression/AvxDisable.manifest.template
+++ b/Pal/regression/AvxDisable.manifest.template
@@ -3,3 +3,4 @@ loader.argv0_override = AvxDisable
 sgx.require_avx = 0
 sgx.require_avx512 = 0
 sgx.allowed_files.res = file:avxRes
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Bootstrap2.manifest.template b/Pal/regression/Bootstrap2.manifest.template
index f85acdc6..16a62043 100644
--- a/Pal/regression/Bootstrap2.manifest.template
+++ b/Pal/regression/Bootstrap2.manifest.template
@@ -1,2 +1,4 @@
 loader.debug_type = inline
 loader.argv0_override = Bootstrap2
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Bootstrap3.manifest.template b/Pal/regression/Bootstrap3.manifest.template
index dacbcab4..5007f81b 100644
--- a/Pal/regression/Bootstrap3.manifest.template
+++ b/Pal/regression/Bootstrap3.manifest.template
@@ -1,3 +1,5 @@
 loader.debug_type = inline
 loader.preload = file:Preload1.so,file:Preload2.so
 loader.argv0_override = Bootstrap3
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Bootstrap4.manifest.template b/Pal/regression/Bootstrap4.manifest.template
index 12e8e3a8..f75facad 100644
--- a/Pal/regression/Bootstrap4.manifest.template
+++ b/Pal/regression/Bootstrap4.manifest.template
@@ -1,2 +1,4 @@
 loader.exec = file:Bootstrap
 loader.argv0_override = Bootstrap
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Bootstrap5.manifest.template b/Pal/regression/Bootstrap5.manifest.template
index 57ad0cdc..8f9eb7c8 100644
--- a/Pal/regression/Bootstrap5.manifest.template
+++ b/Pal/regression/Bootstrap5.manifest.template
@@ -2,3 +2,5 @@ loader.debug_type = inline
 loader.preload = file:Preload1.so,file:Preload2.so
 # This example doesn't use any binary, this line is only to stop argv protection from complaining.
 loader.argv0_override = Bootstrap
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Bootstrap7.manifest.template b/Pal/regression/Bootstrap7.manifest.template
index 60828058..53eeb9bd 100644
--- a/Pal/regression/Bootstrap7.manifest.template
+++ b/Pal/regression/Bootstrap7.manifest.template
@@ -1001,3 +1001,5 @@ loader.env.key997 = na
 loader.env.key998 = na
 loader.env.key999 = na
 loader.env.key1000 = na
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/File.manifest.template b/Pal/regression/File.manifest.template
index d947f508..684be9e4 100644
--- a/Pal/regression/File.manifest.template
+++ b/Pal/regression/File.manifest.template
@@ -11,3 +11,5 @@ sgx.trusted_files.tmp1 = file:File
 sgx.trusted_files.tmp2 = file:../regression/File
 sgx.allowed_files.tmp3 = file:file_nonexist.tmp
 sgx.allowed_files.tmp4 = file:file_delete.tmp
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Process.manifest.template b/Pal/regression/Process.manifest.template
index 267d8010..080a2845 100644
--- a/Pal/regression/Process.manifest.template
+++ b/Pal/regression/Process.manifest.template
@@ -6,3 +6,5 @@ fs.mount.root.uri = file:
 
 net.allow_bind.1 = 127.0.0.1:8000
 net.allow_peer.1 = 127.0.0.1:8000
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Process2.manifest.template b/Pal/regression/Process2.manifest.template
index 62b4e8a2..caeebe0e 100644
--- a/Pal/regression/Process2.manifest.template
+++ b/Pal/regression/Process2.manifest.template
@@ -2,3 +2,5 @@ loader.argv0_override = Process2
 loader.debug_type = inline
 
 sgx.trusted_children.1 = file:Bootstrap.sig
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Process3.manifest.template b/Pal/regression/Process3.manifest.template
index 4e3a7c37..ad7b7567 100644
--- a/Pal/regression/Process3.manifest.template
+++ b/Pal/regression/Process3.manifest.template
@@ -1,3 +1,5 @@
 loader.debug_type = inline
 loader.preload = file:Preload1.so,file:Preload2.so
 loader.insecure__use_cmdline_argv = 1
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/SendHandle.manifest.template b/Pal/regression/SendHandle.manifest.template
index f228f6f8..4f20727f 100644
--- a/Pal/regression/SendHandle.manifest.template
+++ b/Pal/regression/SendHandle.manifest.template
@@ -6,3 +6,5 @@ net.allow_bind.1 = 127.0.0.1:8000
 net.allow_peer.1 = 127.0.0.1:8000
 
 sgx.allowed_files.tmp = file:to_send.tmp
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Thread2.manifest.template b/Pal/regression/Thread2.manifest.template
index adec406b..19d2731f 100644
--- a/Pal/regression/Thread2.manifest.template
+++ b/Pal/regression/Thread2.manifest.template
@@ -2,3 +2,4 @@ loader.argv0_override = Thread2
 
 sgx.thread_num = 2
 sgx.enable_stats = 1
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/Thread2_exitless.manifest.template b/Pal/regression/Thread2_exitless.manifest.template
index 1be05de6..4dcd13bc 100644
--- a/Pal/regression/Thread2_exitless.manifest.template
+++ b/Pal/regression/Thread2_exitless.manifest.template
@@ -4,3 +4,4 @@ loader.argv0_override = Thread2
 sgx.thread_num = 2
 sgx.rpc_thread_num = 2
 sgx.enable_stats = 1
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/manifest.template b/Pal/regression/manifest.template
index 1f11641b..1695e255 100644
--- a/Pal/regression/manifest.template
+++ b/Pal/regression/manifest.template
@@ -5,3 +5,5 @@ fs.mount.root.uri = file:
 
 net.allow_bind.1 = 127.0.0.1:8000
 net.allow_peer.1 = 127.0.0.1:8000
+
+sgx.zero_heap_on_demand = 1
diff --git a/Pal/regression/nonelf_binary.manifest.template b/Pal/regression/nonelf_binary.manifest.template
index e32f2a9e..76b51464 100644
--- a/Pal/regression/nonelf_binary.manifest.template
+++ b/Pal/regression/nonelf_binary.manifest.template
@@ -1,2 +1,4 @@
 loader.exec = file:./nonelf_binary
 loader.debug_type = inline
+
+sgx.zero_heap_on_demand = 1