diff --git a/eclass/toolchain.eclass b/eclass/toolchain.eclass
index 0f7ac98056c3..85a74fdeaf9d 100644
--- a/eclass/toolchain.eclass
+++ b/eclass/toolchain.eclass
@@ -2336,6 +2336,9 @@ gcc_do_make() {
 			STAGE1_CFLAGS="-O0"
 			STAGE1_CXXFLAGS="-O0"
 			STAGE1_GDCFLAGS="-O0"
+
+			# ICEs w/ checking with < GCC 10
+			filter-flags -mtls-dialect=gnu2
 		# We have a very good host compiler but it may be a bit too good, and
 		# know about flags that the version we are compiling does not know
 		# about. In principle we could check e.g. which gnat1 we are using as