diff --git a/src/mzscheme/src/eval.c b/src/mzscheme/src/eval.c
index b48d0d04b1..5d9b7607a9 100644
--- a/src/mzscheme/src/eval.c
+++ b/src/mzscheme/src/eval.c
@@ -163,7 +163,7 @@ static THREAD_LOCAL Scheme_Object *quick_stx;
 /* FIXME needs to be atomically incremented */
 int scheme_overflow_count;
 int get_overflow_count() { return scheme_overflow_count; }
-int scheme_continuation_application_count;
+int THREAD_LOCAL scheme_continuation_application_count;
 
 /* read-only globals */
 Scheme_Object *scheme_eval_waiting;
diff --git a/src/mzscheme/src/fun.c b/src/mzscheme/src/fun.c
index 1352e7ca3d..c8cac95cc0 100644
--- a/src/mzscheme/src/fun.c
+++ b/src/mzscheme/src/fun.c
@@ -89,8 +89,8 @@ Scheme_Object *scheme_tail_call_waiting;
 Scheme_Object *scheme_inferred_name_symbol;
 Scheme_Object *scheme_default_prompt_tag;
 
-int scheme_cont_capture_count;
-int scheme_prompt_capture_count;
+THREAD_LOCAL int scheme_cont_capture_count;
+static THREAD_LOCAL int scheme_prompt_capture_count;
 
 
 /* locals */
diff --git a/src/mzscheme/src/schpriv.h b/src/mzscheme/src/schpriv.h
index 9ce9355243..ab03c1b7e0 100644
--- a/src/mzscheme/src/schpriv.h
+++ b/src/mzscheme/src/schpriv.h
@@ -91,8 +91,8 @@ Scheme_Object *scheme_dump_gc_stats(int c, Scheme_Object *p[]);
 #define REGISTER_SO(x) MZ_REGISTER_STATIC(x)
 
 extern long scheme_total_gc_time;
-extern int scheme_cont_capture_count;
-extern int scheme_continuation_application_count;
+extern THREAD_LOCAL int scheme_cont_capture_count;
+extern THREAD_LOCAL int scheme_continuation_application_count;
 
 int scheme_num_types(void);