diff --git a/source/pem.c b/source/pem.c
index dd8eaf56a..a1a9627be 100644
--- a/source/pem.c
+++ b/source/pem.c
@@ -236,7 +236,7 @@ int s_extract_header_type_cur(struct aws_byte_cursor cur, struct aws_byte_cursor
     struct aws_byte_cursor type_cur = aws_byte_cursor_advance(&cur, cur.len - s_delim_cur.len);
 
     if (!aws_byte_cursor_eq(&cur, &s_delim_cur)) {
-        AWS_LOGF_ERROR(AWS_LS_IO_PEM, "Invalid PEM buffer: invalid end token");
+        AWS_LOGF_ERROR(AWS_LS_IO_PEM, "Invalid PEM buffer: invalid end token :"PRInSTR, AWS_BYTE_CURSOR_PRI(cur));
         return aws_raise_error(AWS_ERROR_PEM_MALFORMED);
     }