diff --git a/eris.c b/eris.c
index a6e18ff..434fcb2 100644
--- a/eris.c
+++ b/eris.c
@@ -319,7 +319,7 @@ serve_file(int fd, char *filename, struct stat *st)
         badrequest(405, "Method Not Supported", "POST is not supported by this URL");
     }
 
-    if (st->st_mtime < ims) {
+    if (st->st_mtime <= ims) {
         header(304, "Not Changed");
         eoh();
         return;
diff --git a/test.sh b/test.sh
index 22599ed..d51c9d9 100755
--- a/test.sh
+++ b/test.sh
@@ -130,6 +130,10 @@ H "If-Modified-Since"
 title "Has been modified"
 printf 'GET / HTTP/1.0\r\nIf-Modified-Since: Sun, 27 Feb 1980 12:12:12 GMT\r\n\r\n' | $HTTPD 2>/dev/null | grep -q 'HTTP/1.. 200 ' && pass || fail
 
+title "Exact same date"
+ims=$(printf 'GET / HTTP/1.0\r\n\r\n' | $HTTPD 2>/dev/null | awk -F ': ' '/Last-Modified/ {print $2;}')
+printf 'GET / HTTP/1.0\r\nIf-Modified-Since: %s\r\n\r\n' "$ims" | $HTTPD 2>/dev/null | grep -q 'HTTP/1.. 304 ' && pass || fail
+
 title "RFC 822 Date"
 printf 'GET / HTTP/1.0\r\nIf-Modified-Since: Sun, 27 Feb 2030 12:12:12 GMT\r\n\r\n' | $HTTPD 2>/dev/null | grep -q 'HTTP/1.. 304 ' && pass || fail