diff --git a/corrvir/corr.h b/corrvir/corr.h
index 9030ee50d60e9ab5d3be94393172aee3cbee9a15..b0a320fee64c7e19d8910f2c87fdfc5c96f5abd8 100644
--- a/corrvir/corr.h
+++ b/corrvir/corr.h
@@ -12,7 +12,7 @@ typedef struct _traceCoord { /* Type */
 	int x;
 	int y;
 	int peg;
-	int fpos;
+	size_t fpos;
 } traceCoord;
 
 typedef struct _crgPos { /* Type */