diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8a58eae..630d59b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -10,23 +10,25 @@ cache:
 
 before_script:
   - crystal -v # Print out Crystal version for debugging
-  - shards
 
 spec:
   script:
-  - crystal spec --error-on-warnings
+    - shards
+    - crystal spec --error-on-warnings
 
 style:
   script:
-  - bin/ameba
-  - crystal tool format --check
+    - shards
+    - bin/ameba
+    - crystal tool format --check
 
 nightly:
   image: "crystallang/crystal:nightly"
   allow_failure: true
   script:
-  - crystal spec --error-on-warnings
-  - crystal tool format --check
+    - shards --ignore-crystal-version
+    - crystal spec --error-on-warnings
+    - crystal tool format --check
 
 pages:
   stage: deploy
diff --git a/shard.yml b/shard.yml
index d0038ce..a6ba14f 100644
--- a/shard.yml
+++ b/shard.yml
@@ -1,5 +1,5 @@
 name: spectator
-version: 0.9.20
+version: 0.9.22
 description: |
   A feature-rich spec testing framework for Crystal with similarities to RSpec.
 
@@ -13,4 +13,4 @@ license: MIT
 development_dependencies:
   ameba:
     github: crystal-ameba/ameba
-    version: ~> 0.12.0
+    version: ~> 0.13.1
diff --git a/src/spectator.cr b/src/spectator.cr
index 9c4907c..77c333e 100644
--- a/src/spectator.cr
+++ b/src/spectator.cr
@@ -6,7 +6,7 @@ module Spectator
   extend self
 
   # Current version of the Spectator library.
-  VERSION = "0.9.20"
+  VERSION = "0.9.22"
 
   # Top-level describe method.
   # All specs in a file must be wrapped in this call.
@@ -45,7 +45,7 @@ module Spectator
     end
   end
 
-  # ditto
+  # :ditto:
   macro context(description, &block)
     describe({{description}}) {{block}}
   end
diff --git a/src/spectator/command_line_arguments_config_source.cr b/src/spectator/command_line_arguments_config_source.cr
index 7b31e99..ce3c7e5 100644
--- a/src/spectator/command_line_arguments_config_source.cr
+++ b/src/spectator/command_line_arguments_config_source.cr
@@ -61,7 +61,7 @@ module Spectator
     private def seed_option(parser, builder)
       parser.on("--seed INTEGER", "Set the seed for the random number generator (implies -r)") do |seed|
         builder.randomize
-        builder.seed = seed.to_i
+        builder.seed = seed.to_u64
       end
     end
 
@@ -74,7 +74,7 @@ module Spectator
         when /^rand/
           builder.randomize
           parts = method.split(':', 2)
-          builder.seed = parts[1].to_i if parts.size > 1
+          builder.seed = parts[1].to_u64 if parts.size > 1
         else
           nil
         end
diff --git a/src/spectator/config.cr b/src/spectator/config.cr
index b7a1eda..a44564b 100644
--- a/src/spectator/config.cr
+++ b/src/spectator/config.cr
@@ -19,6 +19,9 @@ module Spectator
     # Indicates whether tests are run in a random order.
     getter? randomize : Bool
 
+    # Random seed used for number generation.
+    getter! random_seed : UInt64?
+
     # Indicates whether profiling information should be displayed.
     getter? profile : Bool
 
@@ -33,6 +36,7 @@ module Spectator
       @dry_run = builder.dry_run?
       @random = builder.random
       @randomize = builder.randomize?
+      @random_seed = builder.seed?
       @profile = builder.profile?
       @example_filter = builder.example_filter
     end
diff --git a/src/spectator/config_builder.cr b/src/spectator/config_builder.cr
index c650945..d65ffc1 100644
--- a/src/spectator/config_builder.cr
+++ b/src/spectator/config_builder.cr
@@ -11,6 +11,11 @@ module Spectator
     # Random number generator to use.
     protected getter random = Random::DEFAULT
 
+    def initialize
+      @seed = seed = @random.rand(UInt16).to_u64
+      @random.new_seed(seed)
+    end
+
     @primary_formatter : Formatting::Formatter?
     @additional_formatters = [] of Formatting::Formatter
     @fail_fast = false
@@ -90,8 +95,12 @@ module Spectator
       @dry_run
     end
 
+    # Seed used for random number generation.
+    getter! seed : UInt64?
+
     # Sets the seed for the random number generator.
     def seed=(seed)
+      @seed = seed
       @random = Random.new(seed)
     end
 
diff --git a/src/spectator/dsl/assertions.cr b/src/spectator/dsl/assertions.cr
index aa94b13..11b5ffe 100644
--- a/src/spectator/dsl/assertions.cr
+++ b/src/spectator/dsl/assertions.cr
@@ -207,7 +207,7 @@ module Spectator
       raise ExampleFailed.new(reason)
     end
 
-    # ditto
+    # :ditto:
     @[AlwaysInline]
     def fail
       fail("Example failed")
diff --git a/src/spectator/dsl/matchers.cr b/src/spectator/dsl/matchers.cr
index 3a2a703..a9f1030 100644
--- a/src/spectator/dsl/matchers.cr
+++ b/src/spectator/dsl/matchers.cr
@@ -450,8 +450,13 @@ module Spectator
     # expect(%i[a b c]).to contain(:a, :b)
     # ```
     macro contain(*expected)
-      %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.splat.stringify}})
-      ::Spectator::Matchers::ContainMatcher.new(%test_value)
+      {% if expected.id.starts_with?("{*") %}
+        %test_value = ::Spectator::TestValue.new({{expected.id[2...-1]}}, {{expected.splat.stringify}})
+        ::Spectator::Matchers::ContainMatcher.new(%test_value)
+      {% else %}
+        %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.splat.stringify}})
+        ::Spectator::Matchers::ContainMatcher.new(%test_value)
+      {% end %}
     end
 
     # Indicates that some range (or collection) should contain another value.
@@ -471,8 +476,13 @@ module Spectator
     # expect(..100).to contain(0, 50)
     # ```
     macro cover(*expected)
-      %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.splat.stringify}})
-      ::Spectator::Matchers::ContainMatcher.new(%test_value)
+      {% if expected.id.starts_with?("{*") %}
+        %test_value = ::Spectator::TestValue.new({{expected.id[2...-1]}}, {{expected.splat.stringify}})
+        ::Spectator::Matchers::ContainMatcher.new(%test_value)
+      {% else %}
+        %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.splat.stringify}})
+        ::Spectator::Matchers::ContainMatcher.new(%test_value)
+      {% end %}
     end
 
     # Indicates that some value or set should contain another value.
@@ -501,8 +511,13 @@ module Spectator
     # expect(%w[FOO BAR BAZ]).to have(/foo/i, String)
     # ```
     macro have(*expected)
-      %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.splat.stringify}})
-      ::Spectator::Matchers::HaveMatcher.new(%test_value)
+      {% if expected.id.starts_with?("{*") %}
+        %test_value = ::Spectator::TestValue.new({{expected.id[2...-1]}}, {{expected.splat.stringify}})
+        ::Spectator::Matchers::HaveMatcher.new(%test_value)
+      {% else %}
+        %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.splat.stringify}})
+        ::Spectator::Matchers::HaveMatcher.new(%test_value)
+      {% end %}
     end
 
     # Indicates that some set, such as a `Hash`, has a given key.
@@ -518,7 +533,7 @@ module Spectator
       ::Spectator::Matchers::HaveKeyMatcher.new(%test_value)
     end
 
-    # ditto
+    # :ditto:
     macro has_key(expected)
       have_key({{expected}})
     end
@@ -536,7 +551,7 @@ module Spectator
       ::Spectator::Matchers::HaveValueMatcher.new(%test_value)
     end
 
-    # ditto
+    # :ditto:
     macro has_value(expected)
       have_value({{expected}})
     end
@@ -548,8 +563,13 @@ module Spectator
     # expect([1, 2, 3]).to contain_exactly(3, 2, 1)
     # ```
     macro contain_exactly(*expected)
-      %test_value = ::Spectator::TestValue.new(({{expected}}).to_a, {{expected.stringify}})
-      ::Spectator::Matchers::ArrayMatcher.new(%test_value)
+      {% if expected.id.starts_with?("{*") %}
+        %test_value = ::Spectator::TestValue.new(({{expected.id[2...-1]}}).to_a, {{expected.stringify}})
+        ::Spectator::Matchers::ArrayMatcher.new(%test_value)
+      {% else %}
+        %test_value = ::Spectator::TestValue.new(({{expected}}).to_a, {{expected.stringify}})
+        ::Spectator::Matchers::ArrayMatcher.new(%test_value)
+      {% end %}
     end
 
     # Indicates that some set should contain the same values in any order as another set.
@@ -597,8 +617,13 @@ module Spectator
     # expect(%i[a b c]).to have_attributes(size: 1..5, first: Symbol)
     # ```
     macro have_attributes(**expected)
-      %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.double_splat.stringify}})
-      ::Spectator::Matchers::AttributesMatcher.new(%test_value)
+      {% if expected.id.starts_with?("{**") %}
+        %test_value = ::Spectator::TestValue.new({{expected.id[3...-1]}}, {{expected.double_splat.stringify}})
+        ::Spectator::Matchers::AttributesMatcher.new(%test_value)
+      {% else %}
+        %test_value = ::Spectator::TestValue.new({{expected}}, {{expected.double_splat.stringify}})
+        ::Spectator::Matchers::AttributesMatcher.new(%test_value)
+      {% end %}
     end
 
     # Verifies that all elements of a collection satisfy some matcher.
diff --git a/src/spectator/expectations/expectation_partial.cr b/src/spectator/expectations/expectation_partial.cr
index 6a38301..c837c86 100644
--- a/src/spectator/expectations/expectation_partial.cr
+++ b/src/spectator/expectations/expectation_partial.cr
@@ -52,7 +52,7 @@ module Spectator::Expectations
       stubs.each { |stub| to_not(stub) }
     end
 
-    # ditto
+    # :ditto:
     @[AlwaysInline]
     def not_to(matcher) : Nil
       to_not(matcher)
@@ -86,7 +86,7 @@ module Spectator::Expectations
       to_not(stub)
     end
 
-    # ditto
+    # :ditto:
     @[AlwaysInline]
     def never_to(matcher) : Nil
       to_never(matcher)
diff --git a/src/spectator/formatting/random_seed_text.cr b/src/spectator/formatting/random_seed_text.cr
new file mode 100644
index 0000000..998fed1
--- /dev/null
+++ b/src/spectator/formatting/random_seed_text.cr
@@ -0,0 +1,14 @@
+module Spectator::Formatting
+  # Text displayed when using a random seed.
+  private struct RandomSeedText
+    # Creates the text object.
+    def initialize(@seed : UInt64)
+    end
+
+    # Appends the command to the output.
+    def to_s(io)
+      io << "Randomized with seed "
+      io << @seed
+    end
+  end
+end
diff --git a/src/spectator/formatting/suite_summary.cr b/src/spectator/formatting/suite_summary.cr
index 3d2dcfd..183a78e 100644
--- a/src/spectator/formatting/suite_summary.cr
+++ b/src/spectator/formatting/suite_summary.cr
@@ -49,6 +49,10 @@ module Spectator::Formatting
     private def stats(report)
       @io.puts Runtime.new(report.runtime)
       @io.puts StatsCounter.new(report).color
+      if (seed = report.random_seed?)
+        @io.puts
+        @io.puts RandomSeedText.new(seed)
+      end
     end
 
     # Produces the skipped tests text if fail-fast is enabled and tests were omitted.
diff --git a/src/spectator/report.cr b/src/spectator/report.cr
index 54cbb95..9ce1ebd 100644
--- a/src/spectator/report.cr
+++ b/src/spectator/report.cr
@@ -25,12 +25,16 @@ module Spectator
     # This will be greater than zero only in fail-fast mode.
     getter remaining_count
 
+    # Random seed used to determine test ordering.
+    getter! random_seed : UInt64?
+
     # Creates the report.
     # The *results* are from running the examples in the test suite.
     # The *runtime* is the total time it took to execute the suite.
     # The *remaining_count* is the number of tests skipped due to fail-fast.
     # The *fail_blank* flag indicates whether it is a failure if there were no tests run.
-    def initialize(@results : Array(Result), @runtime, @remaining_count = 0, @fail_blank = false)
+    # The *random_seed* is the seed used for random number generation.
+    def initialize(@results : Array(Result), @runtime, @remaining_count = 0, @fail_blank = false, @random_seed = nil)
       @results.each do |result|
         case result
         when SuccessfulResult
diff --git a/src/spectator/runner.cr b/src/spectator/runner.cr
index 8bde725..d5c50f9 100644
--- a/src/spectator/runner.cr
+++ b/src/spectator/runner.cr
@@ -25,7 +25,8 @@ module Spectator
 
       # Generate a report and pass it along to the formatter.
       remaining = @suite.size - results.size
-      report = Report.new(results, elapsed, remaining, @config.fail_blank?)
+      seed = (@config.random_seed? if @config.randomize?)
+      report = Report.new(results, elapsed, remaining, @config.fail_blank?, seed)
       @config.each_formatter(&.end_suite(report, profile(report)))
 
       !report.failed?