diff --git a/src/common/objects/dobjgc.cpp b/src/common/objects/dobjgc.cpp
index f8a5ceb632..e407d3d774 100644
--- a/src/common/objects/dobjgc.cpp
+++ b/src/common/objects/dobjgc.cpp
@@ -125,7 +125,7 @@ EGCState State = GCS_Pause;
 int Pause = DEFAULT_GCPAUSE;
 int StepMul = DEFAULT_GCMUL;
 int StepCount;
-int CheckTime;
+uint64_t CheckTime;
 bool FinalGC;
 
 // PRIVATE DATA DEFINITIONS ------------------------------------------------
diff --git a/src/common/objects/dobjgc.h b/src/common/objects/dobjgc.h
index 2bca366165..1fd2932631 100644
--- a/src/common/objects/dobjgc.h
+++ b/src/common/objects/dobjgc.h
@@ -71,7 +71,7 @@ namespace GC
 	extern bool FinalGC;
 
 	// Counts the number of times CheckGC has been called.
-	extern int CheckTime;
+	extern uint64_t CheckTime;
 
 	// Current white value for known-dead objects.
 	static inline uint32_t OtherWhite()