diff --git a/MozillaFirefox.changes b/MozillaFirefox.changes
index 4d6df0e..9ad8995 100644
--- a/MozillaFirefox.changes
+++ b/MozillaFirefox.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Mon Jan 24 07:42:03 UTC 2022 - Martin Liška <mliska@suse.cz>
+
+- Enable -fimplicit-constexpr for GCC 12+.
+
 -------------------------------------------------------------------
 Thu Jan 20 23:21:44 UTC 2022 - Andreas Stieger <andreas.stieger@gmx.de>
 
diff --git a/MozillaFirefox.spec b/MozillaFirefox.spec
index 01ae667..77cc1a2 100644
--- a/MozillaFirefox.spec
+++ b/MozillaFirefox.spec
@@ -401,6 +401,9 @@ export CC=gcc-9
 %if 0%{?clang_build} == 0
 export CC=gcc
 export CXX=g++
+%if 0%{?gcc_version:%{gcc_version}} >= 12
+export CFLAGS="$CFLAGS -fimplicit-constexpr"
+%endif
 %endif
 %endif
 %ifarch %arm %ix86