diff --git a/postgresql-datalayout-mismatch-on-s390.patch b/postgresql-datalayout-mismatch-on-s390.patch
new file mode 100644
index 0000000..eef0378
--- /dev/null
+++ b/postgresql-datalayout-mismatch-on-s390.patch
@@ -0,0 +1,99 @@
+From 0edaa982336823d4d7af8f10b91579fe0099ef3d Mon Sep 17 00:00:00 2001
+From: Tom Stellard <tstellar@redhat.com>
+Date: Tue, 20 Apr 2021 20:14:21 -0700
+Subject: [PATCH] jit: Workaround potential datalayout mismatch on s390x
+
+LLVM's s390x target uses a different datalayout for z13 and newer processors.
+If llvmjit_types.bc is compiled to target a processor older than z13, and
+then the JIT runs on a z13 or newer processor, then there will be a mismatch
+in datalayouts between llvmjit_types.bc and the JIT engine.  This mismatch
+causes the JIT to fail at runtime.
+---
+ src/backend/jit/llvm/llvmjit.c | 46 ++++++++++++++++++++++++++++++++--
+ 1 file changed, 44 insertions(+), 2 deletions(-)
+
+diff --git a/src/backend/jit/llvm/llvmjit.c b/src/backend/jit/llvm/llvmjit.c
+index 98a27f08bf..05b6438ba8 100644
+--- a/src/backend/jit/llvm/llvmjit.c
++++ b/src/backend/jit/llvm/llvmjit.c
+@@ -776,6 +776,35 @@ llvm_compile_module(LLVMJitContext *context)
+ 			 errhidecontext(true)));
+ }
+ 
++/*
++ * For the systemz target, LLVM uses a different datalayout for z13 and newer
++ * CPUs than it does for older CPUs.  This can cause a mismatch in datalayouts
++ * in the case where the llvm_types_module is compiled with a pre-z13 CPU
++ * and the JIT is running on z13 or newer.
++ * See computeDataLayout() function in
++ * llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp for information on the
++ * datalayout differences.
++ */
++static bool
++needs_systemz_workaround(void)
++{
++	bool ret = false;
++	LLVMContextRef llvm_context;
++	LLVMTypeRef vec_type;
++	LLVMTargetDataRef llvm_layoutref;
++	if (strncmp(LLVMGetTargetName(llvm_targetref), "systemz", strlen("systemz")))
++	{
++		return false;
++	}
++
++	llvm_context = LLVMGetModuleContext(llvm_types_module);
++	vec_type = LLVMVectorType(LLVMIntTypeInContext(llvm_context, 32), 4);
++	llvm_layoutref = LLVMCreateTargetData(llvm_layout);
++	ret = (LLVMABIAlignmentOfType(llvm_layoutref, vec_type) == 16);
++	LLVMDisposeTargetData(llvm_layoutref);
++	return ret;
++}
++
+ /*
+  * Per session initialization.
+  */
+@@ -785,6 +814,7 @@ llvm_session_initialize(void)
+ 	MemoryContext oldcontext;
+ 	char	   *error = NULL;
+ 	char	   *cpu = NULL;
++	char       *host_features = NULL;
+ 	char	   *features = NULL;
+ 	LLVMTargetMachineRef opt0_tm;
+ 	LLVMTargetMachineRef opt3_tm;
+@@ -816,10 +846,17 @@ llvm_session_initialize(void)
+ 	 * features not all CPUs have (weird, huh).
+ 	 */
+ 	cpu = LLVMGetHostCPUName();
+-	features = LLVMGetHostCPUFeatures();
++	features = host_features = LLVMGetHostCPUFeatures();
+ 	elog(DEBUG2, "LLVMJIT detected CPU \"%s\", with features \"%s\"",
+ 		 cpu, features);
+ 
++	if (needs_systemz_workaround())
++	{
++		const char *no_vector =",-vector";
++		features = malloc(sizeof(char) * (strlen(host_features) + strlen(no_vector) + 1));
++		sprintf(features, "%s%s", host_features, no_vector);
++	}
++
+ 	opt0_tm =
+ 		LLVMCreateTargetMachine(llvm_targetref, llvm_triple, cpu, features,
+ 								LLVMCodeGenLevelNone,
+@@ -833,8 +870,13 @@ llvm_session_initialize(void)
+ 
+ 	LLVMDisposeMessage(cpu);
+ 	cpu = NULL;
+-	LLVMDisposeMessage(features);
++	if (features != host_features)
++	{
++		free(features);
++	}
+ 	features = NULL;
++	LLVMDisposeMessage(host_features);
++	host_features = NULL;
+ 
+ 	/* force symbols in main binary to be loaded */
+ 	LLVMLoadLibraryPermanently(NULL);
+-- 
+2.27.0
+
diff --git a/postgresql.spec b/postgresql.spec
index f2400e5..3384d82 100644
--- a/postgresql.spec
+++ b/postgresql.spec
@@ -32,9 +32,7 @@
 %{!?beta:%global beta 0}
 
 %{!?test:%global test 1}
-# Disable temporarily to be able to build the package
-# tracked in RHBZ#1940964
-%{!?llvmjit:%global llvmjit 0}
+%{!?llvmjit:%global llvmjit 1}
 %{!?upgrade:%global upgrade 1}
 %{!?plpython3:%global plpython3 1}
 %{!?pltcl:%global pltcl 1}
@@ -62,7 +60,7 @@ Summary: PostgreSQL client programs
 Name: postgresql
 %global majorversion 13
 Version: %{majorversion}.2
-Release: 5%{?dist}
+Release: 6%{?dist}
 
 # The PostgreSQL license is very similar to other MIT licenses, but the OSI
 # recognizes it as an independent license, so we do as well.
@@ -109,6 +107,9 @@ Patch2: postgresql-logging.patch
 Patch5: postgresql-var-run-socket.patch
 Patch8: postgresql-external-libpq.patch
 Patch9: postgresql-server-pg_config.patch
+# Upstream bug #16971: https://www.postgresql.org/message-id/16971-5d004d34742a3d35%40postgresql.org
+# rhbz#1940964
+Patch10: postgresql-datalayout-mismatch-on-s390.patch
 
 BuildRequires: make
 BuildRequires: gcc
@@ -377,6 +378,7 @@ goal of accelerating analytics queries.
 %patch5 -p1
 %patch8 -p1
 %patch9 -p1
+%patch10 -p1
 
 # We used to run autoconf here, but there's no longer any real need to,
 # since Postgres ships with a reasonably modern configure script.
@@ -1125,6 +1127,11 @@ make -C postgresql-setup-%{setup_version} check
 
 
 %changelog
+* Thu Apr 22 2021 Honza Horak <hhorak@redhat.com> - 13.2-6
+- Fix jit failure on s390x
+  Thanks to Tom Stellard
+  Related: #1940964
+
 * Tue Apr 20 2021 Honza Horak <hhorak@redhat.com> - 13.2-5
 - Add macro for llvmjit settings