diff --git a/DESCRIPTION b/DESCRIPTION
index 5fc57ef..dd7790a 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: secretbase
 Type: Package
 Title: Cryptographic Hash, Extendable-Output and Base64 Functions
-Version: 1.0.3
+Version: 1.0.3.9000
 Description: Fast and memory-efficient streaming hash functions and base64
     encoding / decoding. Hashes strings and raw vectors directly. Stream hashes
     files potentially larger than memory, as well as in-memory objects through
diff --git a/NEWS.md b/NEWS.md
index f3b5583..f17be70 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,5 @@
+# secretbase 1.0.3.9000 (development)
+
 # secretbase 1.0.3
 
 * `base64dec()` now emits a suppressable warning when failing to convert back to a character string.
diff --git a/tests/tests.R b/tests/tests.R
index 2bd2400..c42745b 100644
--- a/tests/tests.R
+++ b/tests/tests.R
@@ -1,8 +1,8 @@
-# minitest - a minimal testing framework v0.0.1 --------------------------------
+# minitest - a minimal testing framework v0.0.2 --------------------------------
 test_library <- function(package) library(package = package, character.only = TRUE)
 test_type <- function(type, x) invisible(typeof(x) == type || {stop("object of type '", typeof(x), "' was returned instead of '", type, "'")})
 test_equal <- function(a, b) invisible(a == b || {print(a); print(b); stop("the above expressions were not equal")})
-test_error <- function(x, containing = "") invisible(inherits(x <- tryCatch(x, error = identity), "error") && grepl(containing, x[["message"]], fixed = TRUE) || stop("expected error message containing '", containing, "' was not generated"))
+test_error <- function(x, containing = "") invisible(inherits(x <- tryCatch(x, error = identity), "error") && grepl(containing, x[["message"]], fixed = TRUE) || stop("Expected error message containing: ", containing, "\nActual error message: ", x[["message"]]))
 # ------------------------------------------------------------------------------
 
 test_library("secretbase")