diff --git a/.firefox.metadata b/.firefox.metadata
index 2fcf433..e5440fe 100644
--- a/.firefox.metadata
+++ b/.firefox.metadata
@@ -1,6 +1,6 @@
 b963b16f6879c5dbe6e33a3a3da058b494453922 SOURCES/cbindgen-vendor.tar.xz
-c9051c7d9ac83384e3c049090861cbe449595e23 SOURCES/firefox-115.4.0esr.processed-source.tar.xz
-0a64220feb8757a00f38d37c6aba3180d2c265dd SOURCES/firefox-langpacks-115.4.0esr-20231017.tar.xz
+f19b5467588701056ebbecc4e4e1e12a07be06f5 SOURCES/firefox-115.5.0esr.processed-source.tar.xz
+04fd448a519fc232595fdff573e38c7d5daa1d05 SOURCES/firefox-langpacks-115.5.0esr-20231114.tar.xz
 2d8a6b2b30d5496735f49ffe8c8a7ede3a78a5ca SOURCES/mochitest-python.tar.gz
 d744f92e874688cc4b5376477dfdd639a97a6cd4 SOURCES/nspr-4.35.0-1.el8_1.src.rpm
 9555ba179bc1398fbacfa2896e45f3808d94ecd2 SOURCES/nss-3.90.0-3.el8_1.src.rpm
diff --git a/.gitignore b/.gitignore
index be27f70..96e2494 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,6 @@
 SOURCES/cbindgen-vendor.tar.xz
-SOURCES/firefox-115.4.0esr.processed-source.tar.xz
-SOURCES/firefox-langpacks-115.4.0esr-20231017.tar.xz
+SOURCES/firefox-115.5.0esr.processed-source.tar.xz
+SOURCES/firefox-langpacks-115.5.0esr-20231114.tar.xz
 SOURCES/mochitest-python.tar.gz
 SOURCES/nspr-4.35.0-1.el8_1.src.rpm
 SOURCES/nss-3.90.0-3.el8_1.src.rpm
diff --git a/SPECS/firefox.spec b/SPECS/firefox.spec
index eeda0a3..46c34dc 100644
--- a/SPECS/firefox.spec
+++ b/SPECS/firefox.spec
@@ -24,7 +24,7 @@ function dist_to_rhel_minor(str, start)
   end
   match = string.match(str, ".el8")
   if match then
-     return 9
+     return 10
   end
   match = string.match(str, ".module%+el9.%d+")
   if match then
@@ -36,7 +36,7 @@ function dist_to_rhel_minor(str, start)
   end
   match = string.match(str, ".el9")
   if match then
-     return 3
+     return 4
   end
   return -1
 end}
@@ -132,7 +132,7 @@ end}
 
 Summary:        Mozilla Firefox Web browser
 Name:           firefox
-Version:        115.4.0
+Version:        115.5.0
 Release:        1%{?dist}.inferit
 URL:            https://www.mozilla.org/firefox/
 License:        MPLv1.1 or GPLv2+ or LGPLv2+
@@ -141,10 +141,15 @@ License:        MPLv1.1 or GPLv2+ or LGPLv2+
 ExcludeArch:    %{ix86}
 %endif
 %if 0%{?rhel} == 8
+  # Started to ship on aarch64 in RHEL 8.2, on s390x in RHEL 8.3
   %if %{rhel_minor_version} == 1
-ExcludeArch:    %{ix86} aarch64 s390x
+ExcludeArch:    %{ix86} s390x aarch64
   %else
+    %if %{rhel_minor_version} == 2
+ExcludeArch:    %{ix86} s390x
+    %else
 ExcludeArch:    %{ix86}
+    %endif
   %endif
 %endif
 %if 0%{?rhel} == 7
@@ -158,7 +163,7 @@ ExcludeArch:    aarch64 s390 ppc
 # Link to original tarball: https://archive.mozilla.org/pub/firefox/releases/%%{version}%%{?pre_version}/source/firefox-%%{version}%%{?pre_version}.source.tar.xz
 Source0:        firefox-%{version}%{?pre_version}%{?buildnum}.processed-source.tar.xz
 %if %{with langpacks}
-Source1:        firefox-langpacks-%{version}%{?pre_version}-20231017.tar.xz
+Source1:        firefox-langpacks-%{version}%{?pre_version}-20231114.tar.xz
 %endif
 Source2:        cbindgen-vendor.tar.xz
 Source3:        process-official-tarball
@@ -1134,6 +1139,13 @@ echo "ac_add_options --with-mozilla-api-keyfile=`pwd`/mozilla-api-key" >> .mozco
 echo "ac_add_options --with-google-location-service-api-keyfile=`pwd`/google-loc-api-key" >> .mozconfig
 echo "ac_add_options --with-google-safebrowsing-api-keyfile=`pwd`/google-api-key" >> .mozconfig
 
+# May result in empty --with-libclang-path= in earlier versions.
+# So far this is needed only for c8s.
+%if 0%{?rhel} == 8 && %{rhel_minor_version} >= 10
+# Clang 17 upstream's detection fails, tell it where to look.
+echo "ac_add_options --with-libclang-path=`llvm-config --libdir`" >> .mozconfig
+%endif
+
 echo 'export NODEJS="%{_buildrootdir}/bin/node-stdout-nonblocking-wrapper"' >> .mozconfig
 
 # Remove executable bit to make brp-mangle-shebangs happy.
@@ -1754,7 +1766,10 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #---------------------------------------------------------------------
 
 %changelog
-* Tue Oct 31 2023 Arkady L. Shane <tigro@msvsphere-ru> - 115.4.0-1.inferit
+* Tue Nov 14 2023 Eike Rathke <erack@redhat.com> - 115.5.0-1
+- Update to 115.5.0 build1
+
+* Tue Oct 17 2023 Eike Rathke <erack@redhat.com> - 115.4.0-1
 - Update to 115.4.0 build1
 - Add fix for CVE-2023-44488