diff --git a/src/interpret.h b/src/interpret.h
index 7b00791b506714bbaaf6f4a39119acc236044361..b5087ebb7c3f32ea7f9dea0fbfde293315898031 100644
--- a/src/interpret.h
+++ b/src/interpret.h
@@ -713,7 +713,7 @@ PMOD_EXPORT extern unsigned long evaluator_callback_calls;
     low_check_threads_etc();						\
   } while (0)
 
-extern int fast_check_threads_counter;
+PMOD_EXPORT extern int fast_check_threads_counter;
 
 #define fast_check_threads_etc(X) do {					\
     DO_IF_DEBUG (if (Pike_interpreter.trace_level > 2)			\