diff --git a/lib/github_changelog_generator/generator/generator.rb b/lib/github_changelog_generator/generator/generator.rb
index 04eefad..a3944b8 100644
--- a/lib/github_changelog_generator/generator/generator.rb
+++ b/lib/github_changelog_generator/generator/generator.rb
@@ -11,7 +11,7 @@ module GitHubChangelogGenerator
   end
 
   class Generator
-    attr_accessor :options, :filtered_tags, :github, :tag_section_mapping
+    attr_accessor :options, :filtered_tags, :github, :tag_section_mapping, :sorted_tags
 
     # A Generator responsible for all logic, related with change log generation from ready-to-parse issues
     #
diff --git a/lib/github_changelog_generator/generator/generator_generation.rb b/lib/github_changelog_generator/generator/generator_generation.rb
index c939b7a..4b18fd7 100644
--- a/lib/github_changelog_generator/generator/generator_generation.rb
+++ b/lib/github_changelog_generator/generator/generator_generation.rb
@@ -126,8 +126,9 @@ module GitHubChangelogGenerator
     def generate_unreleased_section
       log = ""
       if options[:unreleased]
-        unreleased_log = generate_log_between_tags(filtered_tags[0], nil)
-        log += unreleased_log if unreleased_log
+        start_tag      = filtered_tags[0] || sorted_tags.last
+        unreleased_log = generate_log_between_tags(start_tag, nil)
+        log           += unreleased_log if unreleased_log
       end
       log
     end
diff --git a/lib/github_changelog_generator/generator/generator_processor.rb b/lib/github_changelog_generator/generator/generator_processor.rb
index 5bbc11a..cf25dc5 100644
--- a/lib/github_changelog_generator/generator/generator_processor.rb
+++ b/lib/github_changelog_generator/generator/generator_processor.rb
@@ -72,6 +72,8 @@ module GitHubChangelogGenerator
       # in case if not tags specified - return unchanged array
       return issues if older_tag.nil? && newer_tag.nil?
 
+      older_tag = ensure_older_tag(older_tag, newer_tag)
+
       newer_tag_time = newer_tag && get_time_of_tag(newer_tag)
       older_tag_time = older_tag && get_time_of_tag(older_tag)
 
@@ -92,6 +94,12 @@ module GitHubChangelogGenerator
       end
     end
 
+    def ensure_older_tag(older_tag, newer_tag)
+      return older_tag if older_tag
+      idx = sorted_tags.index { |t| t["name"] == newer_tag["name"] }
+      sorted_tags[idx - 1]
+    end
+
     def tag_older_new_tag?(newer_tag_time, time)
       tag_in_range_new = if newer_tag_time.nil?
                            true
diff --git a/lib/github_changelog_generator/generator/generator_tags.rb b/lib/github_changelog_generator/generator/generator_tags.rb
index de721d6..01480b5 100644
--- a/lib/github_changelog_generator/generator/generator_tags.rb
+++ b/lib/github_changelog_generator/generator/generator_tags.rb
@@ -10,8 +10,8 @@ module GitHubChangelogGenerator
       included_tags = filter_excluded_tags(all_tags)
 
       fetch_tags_dates(all_tags) # Creates a Hash @tag_times_hash
-      sorted_tags          = sort_tags_by_date(included_tags)
-      @filtered_tags       = get_filtered_tags(included_tags)
+      @sorted_tags   = sort_tags_by_date(included_tags)
+      @filtered_tags = get_filtered_tags(included_tags)
 
       @tag_section_mapping = build_tag_section_mapping(@filtered_tags, sorted_tags)