diff --git a/djpeg.c b/djpeg.c
index e4e8a621..589c5805 100644
--- a/djpeg.c
+++ b/djpeg.c
@@ -566,7 +566,7 @@ main (int argc, char **argv)
         exit(EXIT_FAILURE);
       }
       nbytes = JFREAD(input_file, &inbuffer[insize], INPUT_BUF_SIZE);
-      if (nbytes < 0) {
+      if (nbytes < INPUT_BUF_SIZE && ferror(input_file)) {
         if (file_index < argc)
           fprintf(stderr, "%s: can't read from %s\n", progname,
                   argv[file_index]);
diff --git a/tjbench.c b/tjbench.c
index 105a4cce..1f88e133 100644
--- a/tjbench.c
+++ b/tjbench.c
@@ -475,7 +475,7 @@ void dodecomptest(char *filename)
 
 	if((file=fopen(filename, "rb"))==NULL)
 		_throwunix("opening file");
-	if(fseek(file, 0, SEEK_END)<0 || (srcsize=ftell(file))<0)
+	if(fseek(file, 0, SEEK_END)<0 || (srcsize=ftell(file))==(unsigned long)-1)
 		_throwunix("determining file size");
 	if((srcbuf=(unsigned char *)malloc(srcsize))==NULL)
 		_throwunix("allocating memory");