diff --git a/ChangeLog b/ChangeLog
index 30b97754..c81800da 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,6 +5,9 @@ What's New for OpenJPEG
 ! : changed
 + : added
 
+July 8, 2007
+* [ANTONIN] fixed the size of the memory allocation in cio.c (confusion between bits and bytes)
+
 June 21, 2007
 * [FOD] Output image color space set when decoding a JP2 file in jp2.c
 + [GB] Previous, home, and next frame buttons for exploring MJ2 files in OPJViewer
diff --git a/libopenjpeg/cio.c b/libopenjpeg/cio.c
index 6082e9be..cb0c3e4a 100644
--- a/libopenjpeg/cio.c
+++ b/libopenjpeg/cio.c
@@ -58,7 +58,7 @@ opj_cio_t* OPJ_CALLCONV opj_cio_open(opj_common_ptr cinfo, unsigned char *buffer
 				opj_free(cio);
 				return NULL;
 		}
-		cio->length = (int) (1.3 * cp->img_size);
+		cio->length = (int) (0.1625 * cp->img_size); /* 0.1625 = 1.3/8 */
 		cio->buffer = (unsigned char *)opj_malloc(cio->length);
 		if(!cio->buffer) {
 			opj_free(cio);