diff --git a/CHANGES b/CHANGES
index 1b24c435..abec0302 100644
--- a/CHANGES
+++ b/CHANGES
@@ -6,6 +6,7 @@ What's New for OpenJPEG
 + : added
 
 February 17, 2011
+* [antonin] replaced 'long' by 'size_t' in dwt.c to be sure to cast to a pointer size.
 * [antonin] now allows 16-bit precision for mj2 encoding and decoding (solves Issue 49 and Issue 63). Credit to Winfried.
 
 February 9, 2011
diff --git a/libopenjpeg/dwt.c b/libopenjpeg/dwt.c
index 6f25debd..3436b103 100644
--- a/libopenjpeg/dwt.c
+++ b/libopenjpeg/dwt.c
@@ -570,7 +570,7 @@ static void v4dwt_interleave_h(v4dwt_t* restrict w, float* restrict a, int x, in
 	int count = w->sn;
 	int i, k;
 	for(k = 0; k < 2; ++k){
-		if (count + 3 * x < size && ((long) a & 0x0f) == 0 && ((long) bi & 0x0f) == 0 && (x & 0x0f) == 0) {
+		if (count + 3 * x < size && ((size_t) a & 0x0f) == 0 && ((size_t) bi & 0x0f) == 0 && (x & 0x0f) == 0) {
 			/* Fast code path */
 			for(i = 0; i < count; ++i){
 				int j = i;