diff --git a/app-emulation/wine-proton/wine-proton-7.0.6.ebuild b/app-emulation/wine-proton/wine-proton-7.0.6.ebuild
index 95664cb0ff23e..2d64d08da94fe 100644
--- a/app-emulation/wine-proton/wine-proton-7.0.6.ebuild
+++ b/app-emulation/wine-proton/wine-proton-7.0.6.ebuild
@@ -269,11 +269,13 @@ src_configure() {
 		: "${CROSSCFLAGS:=$(
 			filter-flags '-fstack-protector*' #870136
 			filter-flags '-mfunction-return=thunk*' #878849
+
 			# -mavx with mingw-gcc has a history of obscure issues and
 			# disabling is seen as safer, e.g. `WINEARCH=win32 winecfg`
 			# crashes with -march=skylake >=wine-8.10, similar issues with
 			# znver4: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273
-			use custom-cflags || append-cflags -mno-avx
+			append-cflags -mno-avx #912268
+
 			CC=${CROSSCC} test-flags-CC ${CFLAGS:--O2})}"
 		: "${CROSSLDFLAGS:=$(
 			filter-flags '-fuse-ld=*'
diff --git a/app-emulation/wine-proton/wine-proton-8.0.3c.ebuild b/app-emulation/wine-proton/wine-proton-8.0.3c.ebuild
index c5db812fe92b3..28c682e796967 100644
--- a/app-emulation/wine-proton/wine-proton-8.0.3c.ebuild
+++ b/app-emulation/wine-proton/wine-proton-8.0.3c.ebuild
@@ -273,14 +273,17 @@ src_configure() {
 		: "${CROSSCFLAGS:=$(
 			# >=wine-7.21 <8.10's configure.ac does not pass -fno-strict when
 			# it should (can be removed when proton is rebased on >=8.10)
-			append-cflags '-fno-strict-aliasing'
+			append-cflags -fno-strict-aliasing
+
 			filter-flags '-fstack-protector*' #870136
 			filter-flags '-mfunction-return=thunk*' #878849
+
 			# -mavx with mingw-gcc has a history of obscure issues and
 			# disabling is seen as safer, e.g. `WINEARCH=win32 winecfg`
 			# crashes with -march=skylake >=wine-8.10, similar issues with
 			# znver4: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273
-			use custom-cflags || append-cflags -mno-avx
+			append-cflags -mno-avx #912268
+
 			CC=${CROSSCC} test-flags-CC ${CFLAGS:--O2})}"
 		: "${CROSSLDFLAGS:=$(
 			filter-flags '-fuse-ld=*'
diff --git a/app-emulation/wine-proton/wine-proton-8.0.9999.ebuild b/app-emulation/wine-proton/wine-proton-8.0.9999.ebuild
index 6c5e37bcd5bb7..9c15f5e099957 100644
--- a/app-emulation/wine-proton/wine-proton-8.0.9999.ebuild
+++ b/app-emulation/wine-proton/wine-proton-8.0.9999.ebuild
@@ -277,14 +277,17 @@ src_configure() {
 		: "${CROSSCFLAGS:=$(
 			# >=wine-7.21 <8.10's configure.ac does not pass -fno-strict when
 			# it should (can be removed when proton is rebased on >=8.10)
-			append-cflags '-fno-strict-aliasing'
+			append-cflags -fno-strict-aliasing
+
 			filter-flags '-fstack-protector*' #870136
 			filter-flags '-mfunction-return=thunk*' #878849
+
 			# -mavx with mingw-gcc has a history of obscure issues and
 			# disabling is seen as safer, e.g. `WINEARCH=win32 winecfg`
 			# crashes with -march=skylake >=wine-8.10, similar issues with
 			# znver4: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110273
-			use custom-cflags || append-cflags -mno-avx
+			append-cflags -mno-avx #912268
+
 			CC=${CROSSCC} test-flags-CC ${CFLAGS:--O2})}"
 		: "${CROSSLDFLAGS:=$(
 			filter-flags '-fuse-ld=*'