--- a/extensions/spellcheck/src/moz.build
+++ b/extensions/spellcheck/src/moz.build
@@ -28,3 +28,8 @@ EXPORTS.mozilla += [

 if CONFIG['CC_TYPE'] in ('clang', 'gcc'):
     CXXFLAGS += ['-Wno-error=shadow']
+
+# spell checker triggers bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88561
+# in gcc 7 and 8. It will be fixed in GCC 7.5 and 8.3
+if CONFIG['CC_TYPE'] in ('gcc'):
+    CXXFLAGS += ['-fno-devirtualize']