diff --git a/includes/rts/storage/ClosureTypes.h b/includes/rts/storage/ClosureTypes.h
index 240982ca8560ae508c488c901dfbc7f525d7dc67..443efed5f1cf958842bb4f0f56b4fbad6f6004ce 100644
--- a/includes/rts/storage/ClosureTypes.h
+++ b/includes/rts/storage/ClosureTypes.h
@@ -15,6 +15,7 @@
  * If you add or delete any closure types, don't forget to update the following,
  *   - the closure flags table in rts/ClosureFlags.c
  *   - isRetainer in rts/RetainerProfile.c
+ *   - the closure_type_names list in rts/Printer.c
  */
 
 /* Object tag 0 raises an internal error */
diff --git a/rts/Printer.c b/rts/Printer.c
index f077814ba9b1f1a13544b55fadb6ea591a99e12f..904f23acba0d3c1f4698293a4105b1954a2bc0f0 100644
--- a/rts/Printer.c
+++ b/rts/Printer.c
@@ -820,7 +820,8 @@ void printObj( StgClosure *obj )
 /* -----------------------------------------------------------------------------
    Closure types
 
-   NOTE: must be kept in sync with the closure types in includes/ClosureTypes.h
+   NOTE: must be kept in sync with the closure types in
+   includes/rts/storage/ClosureTypes.h
    -------------------------------------------------------------------------- */
 
 const char *closure_type_names[] = {
@@ -883,9 +884,17 @@ const char *closure_type_names[] = {
  [CATCH_RETRY_FRAME]     = "CATCH_RETRY_FRAME",
  [CATCH_STM_FRAME]       = "CATCH_STM_FRAME",
  [WHITEHOLE]             = "WHITEHOLE",
+ [SMALL_MUT_ARR_PTRS_CLEAN] = "SMALL_MUT_ARR_PTRS_CLEAN",
+ [SMALL_MUT_ARR_PTRS_DIRTY] = "SMALL_MUT_ARR_PTRS_DIRTY",
+ [SMALL_MUT_ARR_PTRS_FROZEN0] = "SMALL_MUT_ARR_PTRS_FROZEN0",
+ [SMALL_MUT_ARR_PTRS_FROZEN] = "SMALL_MUT_ARR_PTRS_FROZEN",
  [COMPACT_NFDATA]        = "COMPACT_NFDATA"
 };
 
+#if N_CLOSURE_TYPES != 64
+#error Closure types changed: update Printer.c!
+#endif
+
 const char *
 info_type(const StgClosure *closure){
   return closure_type_names[get_itbl(closure)->type];