diff --git a/ChangeLog b/ChangeLog
index 7a8752e4..a19d2ce2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,7 @@ What's New for OpenJPEG
 + : added
 
 April 8, 2010
+* [FOD] Fixed JP3D codec file format analyzer. Thanks to Kristóf Ralovich for this patch.
 ! [FOD] Significant optimizations of MCT, DWT, MQ and T1 modules by Peter Wimmer (thanks Peter)
 
 March 26, 2010
diff --git a/jp3d/codec/jp3d_to_volume.c b/jp3d/codec/jp3d_to_volume.c
index 4086b20d..a5614d71 100755
--- a/jp3d/codec/jp3d_to_volume.c
+++ b/jp3d/codec/jp3d_to_volume.c
@@ -196,14 +196,15 @@ int get_file_format(char *filename) {
 	int i;
 	static const char *extension[] = {"pgx", "bin", "j3d", "jp3d", "j2k", "img"};
 	static const int format[] = { PGX_DFMT, BIN_DFMT, J3D_CFMT, J3D_CFMT, J2K_CFMT, IMG_DFMT};
-	char * ext = strrchr(filename, '.') + 1;
-	for(i = 0; i < sizeof(format) / sizeof(format[0]); i++) {
-		if(strnicmp(ext, extension[i], 3) == 0) {
-			return format[i];
+	char * ext = strrchr(filename, '.');
+	if(ext) {
+		ext++;
+		for(i = 0; i < sizeof(format) / sizeof(format[0]); i++) {
+			if(strnicmp(ext, extension[i], 3) == 0) {
+				return format[i];
+			}
 		}
 	}
-
-	return -1;
 }
 
 /* -------------------------------------------------------------------------- */
diff --git a/jp3d/codec/volume_to_jp3d.c b/jp3d/codec/volume_to_jp3d.c
index 84f01e83..da4ca25c 100755
--- a/jp3d/codec/volume_to_jp3d.c
+++ b/jp3d/codec/volume_to_jp3d.c
@@ -215,8 +215,9 @@ int get_file_format(char *filename) {
 	int i;
 	static const char *extension[] = {"pgx", "bin", "img", "j3d", "jp3d", "j2k"};
 	static const int format[] = { PGX_DFMT, BIN_DFMT, IMG_DFMT, J3D_CFMT, J3D_CFMT, J2K_CFMT};
-	char * ext = strrchr(filename, '.') + 1;
+	char * ext = strrchr(filename, '.');
 	if (ext) {
+		ext++;
         for(i = 0; i < sizeof(format)/sizeof(*format); i++) {
 			if(strnicmp(ext, extension[i], 3) == 0) {
                 return format[i];