--- c/addfeatures/hotconv/FeatCtx.cpp
+++ c/addfeatures/hotconv/FeatCtx.cpp
@@ -490,7 +490,8 @@ const GPat::ClassRec &FeatCtx::lookupGlyphClass(const std::string &gcname) {
     auto search = namedGlyphClasses.find(gcname);
     if ( search == namedGlyphClasses.end() ) {
         featMsg(sFATAL, "glyph class not defined");
-        return GPat::ClassRec {};
+        static const GPat::ClassRec empty;
+        return empty;
     }
     return search->second;
 }
--- c/addfeatures/hotconv/GPOS.cpp
+++ c/addfeatures/hotconv/GPOS.cpp
@@ -997,7 +997,7 @@ GPat::ClassRec &GPOS::getCR(uint32_t cls, int classDefInx) {
     g->logger->log(sFATAL, "class <%u> not valid in classDef", cls);
     */
     assert(false);
-    GPat::ClassRec cr;
+    static GPat::ClassRec cr;
     return cr;
 }