diff --git a/CHANGES.md b/CHANGES.md
index d5658fc..725f507 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,5 +1,7 @@
 # Unreleased
 
+- Support older GCC like 4.8.5 (#59)
+
 - Fix spawning processes on Windows when environment contains non-ascii
   characters (#58)
 
diff --git a/src/spawn_stubs.c b/src/spawn_stubs.c
index 95b13b7..c654b5c 100644
--- a/src/spawn_stubs.c
+++ b/src/spawn_stubs.c
@@ -499,8 +499,8 @@ CAMLprim value spawn_unix(value v_env,
         caml_failwith("Unknown sigprocmask action");
     }
 
-    for (value v_signals_list = Field(v_sigprocmask, 1);
-         v_signals_list != Val_emptylist;
+    value v_signals_list = Field(v_sigprocmask, 1);
+    for (; v_signals_list != Val_emptylist;
          v_signals_list = Field(v_signals_list, 1)) {
       int signal = caml_convert_signal_number(Long_val(Field(v_signals_list, 0)));
       switch (sigprocmask_command) {