diff --git a/debian/changelog b/debian/changelog
index 4bc42967..472caae3 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -2,6 +2,7 @@ llvm-toolchain-19 (1:19.1.0~++rc3-1~exp2) UNRELEASED; urgency=medium
 
   * Add a .gitignore file with all toplevel upstream files and directories.
   * Add some memory tracking, getting some information on memory hogs.
+  * Don't require g++-multilib on s390x for newer Ubuntu releases.
 
  -- Matthias Klose <doko@ubuntu.com>  Tue, 27 Aug 2024 11:47:25 +0200
 
diff --git a/debian/control.in b/debian/control.in
index 87bac8fd..8b7ecf75 100644
--- a/debian/control.in
+++ b/debian/control.in
@@ -16,7 +16,7 @@ Build-Depends: debhelper (>= 10.0), cmake, ninja-build,
     libipt-dev [amd64 i386],
     lcov, procps, help2man,
     zlib1g-dev, libzstd-dev,
-    g++-multilib [amd64 i386 kfreebsd-amd64 mips64 mips64el mipsel powerpc ppc64 s390 s390x sparc sparc64 x32],
+    g++-multilib [@MULTILIB_ARCHS@],
     libjs-mathjax, python3-myst-parser | python3-recommonmark, python3-pexpect,
     doxygen,@USAGE_BUILD_DEP@
     ocaml-base [amd64 arm64 armhf ppc64el riscv64 s390x] | ocaml-nox [amd64 arm64 armhf ppc64el riscv64 s390x],
diff --git a/debian/rules b/debian/rules
index ce9d77ca..429204ff 100755
--- a/debian/rules
+++ b/debian/rules
@@ -53,6 +53,9 @@ endif
 
 VENDOR=$(shell lsb_release -is)
 DISTRO=$(shell lsb_release -sc)
+DERIVATIVE := $(shell if dpkg-vendor --derives-from Ubuntu; then echo Ubuntu; \
+		elif dpkg-vendor --derives-from Debian; then echo Debian; \
+		else echo Unknown; fi)
 
 SONAME_EXT      := 1
 SONAME_OPENMP	:= 5
@@ -89,6 +92,13 @@ DH_VERSION := $(shell dpkg -s debhelper | grep '^Version' | awk '{print $$2}')
 
 include /usr/share/dpkg/architecture.mk
 
+MULTILIB_ARCHS := amd64 i386 kfreebsd-amd64 mips64 mips64el mipsel powerpc ppc64 s390 s390x sparc sparc64 x32
+ifeq ($(DERIVATIVE),Ubuntu)
+  ifeq (,$(filter $(DISTRO), bionic focal jammy noble))
+    MULTILIB_ARCHS := $(filter-out s390 s390x, $(MULTILIB_ARCHS))
+  endif
+endif
+
 CONFIGURE_EXTRA =
 
 # these are handled on a per stage / build basis
@@ -166,7 +176,7 @@ endif
 Z3_FLAG = -DLLVM_ENABLE_Z3_SOLVER=OFF
 ifeq ($(shell dpkg --compare-versions $(shell dpkg-query -W -f '$${Version}' libz3-dev) gt 4.7.0; echo $$?),0)
 # no ocaml support in main for Ubuntu
-ifneq ($(shell dpkg-vendor --derives-from Ubuntu && echo yes),yes)
+ifeq ($(DERIVATIVE),Debian)
 	Z3_FLAG = -DLLVM_ENABLE_Z3_SOLVER=ON
 endif
 endif
@@ -174,7 +184,7 @@ STAGE_2_CMAKE_EXTRA += $(Z3_FLAG)
 
 # Change the default CPU for s390x
 ZARCH=z196
-ifeq ($(shell dpkg-vendor --derives-from Ubuntu && echo yes),yes)
+ifeq ($(DERIVATIVE),Ubuntu)
 ZARCH=z13
 endif
 STAGE_2_CMAKE_EXTRA += -DCLANG_SYSTEMZ_DEFAULT_ARCH=$(ZARCH)
@@ -404,7 +414,7 @@ RUN_TEST=yes
 ifneq (,$(filter nocheck,$(DEB_BUILD_OPTIONS)))
 	RUN_TEST=no
 endif
-ifeq ($(shell dpkg-vendor --derives-from Ubuntu && echo yes),yes)
+ifeq ($(DERIVATIVE),Ubuntu)
 ifeq (riscv64,$(DEB_HOST_ARCH))
 	RUN_TEST=no
 endif
@@ -653,6 +663,7 @@ stamps/preconfigure:
 		echo "$$f => $$f2"; \
 		sed -e 's|@DEB_HOST_MULTIARCH@|$(DEB_HOST_MULTIARCH)|g' \
 			-e "s|@USAGE_BUILD_DEP@|$(USAGE_BUILD_DEP)|g" \
+			-e "s|@MULTILIB_ARCHS@|$(MULTILIB_ARCHS)|g" \
 			-e "s|@BRANCH_NAME@|$(BRANCH_NAME)|g" \
 			-e "s|@OCAML_STDLIB_DIR@|$(OCAML_STDLIB_DIR)|g" \
 			-e "s|@LLVM_EPOCH@|$(LLVM_EPOCH)|g" \