diff --git a/valgrind-3.18.1-dhat-tests-copy.patch b/valgrind-3.18.1-dhat-tests-copy.patch
new file mode 100644
index 0000000..8e183b9
--- /dev/null
+++ b/valgrind-3.18.1-dhat-tests-copy.patch
@@ -0,0 +1,20 @@
+commit 33aba8eef68b1745d3de96b609ff8296b70d9a1c
+Author: Paul Floyd <pjfloyd@wanadoo.fr>
+Date:   Wed Oct 27 21:37:00 2021 +0200
+
+    Bug 444495 - dhat/tests/copy fails on s390x
+    
+    Add -fno-builtin to ensure that the copy functions get called and so dhat
+    can intercept and count them.
+
+diff --git a/dhat/tests/Makefile.am b/dhat/tests/Makefile.am
+index 86a9b6d64..b86fc416d 100644
+--- a/dhat/tests/Makefile.am
++++ b/dhat/tests/Makefile.am
+@@ -29,3 +29,6 @@ AM_CXXFLAGS += $(AM_FLAG_M3264_PRI)
+ # We don't care about uninitialized or unused malloc results
+ basic_CFLAGS  = $(AM_CFLAGS) -Wno-uninitialized
+ big_CFLAGS  = $(AM_CFLAGS) -Wno-unused-result
++
++# Prevent the copying functions from being inlined
++copy_CFLAGS = $(AM_CFLAGS) -fno-builtin
diff --git a/valgrind.spec b/valgrind.spec
index 42e6a4b..9501e86 100644
--- a/valgrind.spec
+++ b/valgrind.spec
@@ -85,6 +85,9 @@ Patch4: valgrind-3.16.0-some-stack-protector.patch
 # Add some -Wl,z,now.
 Patch5: valgrind-3.16.0-some-Wl-z-now.patch
 
+# KDE#444495 dhat/tests/copy fails on s390x
+Patch6: valgrind-3.18.1-dhat-tests-copy.patch
+
 BuildRequires: make
 BuildRequires: glibc-devel
 
@@ -222,6 +225,8 @@ Valgrind User Manual for details.
 %patch5 -p1
 %endif
 
+%patch6 -p1
+
 %build
 # LTO triggers undefined symbols in valgrind.  Valgrind has a --enable-lto
 # configure time option, but that doesn't seem to help.
@@ -450,6 +455,9 @@ fi
 %endif
 
 %changelog
+* Mon Nov  1 2021 Mark Wielaard <mjw@fedoraproject.org>
+- Add valgrind-3.18.1-dhat-tests-copy.patch
+
 * Fri Oct 15 2021 Mark Wielaard <mjw@fedoraproject.org> - 3.18.0-1
 - Update to upstream 3.18.1 final