diff --git a/gc.spec b/gc.spec
index 199c9fd..9630bc8 100644
--- a/gc.spec
+++ b/gc.spec
@@ -71,6 +71,7 @@ CPPFLAGS="-DUSE_GET_STACKBASE_FOR_MAIN"; export CPPFLAGS
 %ifarch %{ix86}
   --enable-parallel-mark \
 %endif
+  --enable-threads=posix \
   --with-libatomic-ops=no
 
 make %{?_smp_mflags}