diff --git a/spec/compiler/crystal/tools/doc/project_info_spec.cr b/spec/compiler/crystal/tools/doc/project_info_spec.cr
index 80bc36ddd447..e6c9b5a9742c 100644
--- a/spec/compiler/crystal/tools/doc/project_info_spec.cr
+++ b/spec/compiler/crystal/tools/doc/project_info_spec.cr
@@ -51,6 +51,27 @@ describe Crystal::Doc::ProjectInfo do
         ProjectInfo.new_with_defaults(nil, "1.1") { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("foo", "1.1")
         ProjectInfo.new_with_defaults("bar", "2.0") { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("bar", "2.0")
       end
+
+      it "git non-tagged commit" do
+        `git init`
+        `git add shard.yml`
+        `git commit -m 'Initial commit' --no-gpg-sign`
+
+        ProjectInfo.new_with_defaults(nil, nil) { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("foo", "master")
+        ProjectInfo.new_with_defaults(nil, "1.1") { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("foo", "1.1")
+        ProjectInfo.new_with_defaults("bar", "2.0") { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("bar", "2.0")
+      end
+
+      it "git non-tagged commit dirty" do
+        `git init`
+        `git add shard.yml`
+        `git commit -m 'Initial commit' --no-gpg-sign`
+        File.write("foo.txt", "bar")
+
+        ProjectInfo.new_with_defaults(nil, nil) { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("foo", "master-dev")
+        ProjectInfo.new_with_defaults(nil, "1.1") { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("foo", "1.1")
+        ProjectInfo.new_with_defaults("bar", "2.0") { |name, version| "missing:#{name}:#{version}" }.should eq ProjectInfo.new("bar", "2.0")
+      end
     end
 
     it "no shard.yml, but git tagged version" do
@@ -70,28 +91,44 @@ describe Crystal::Doc::ProjectInfo do
     # Non-git directory
     ProjectInfo.find_git_version.should be_nil
 
+    # Empty git directory
     `git init`
     ProjectInfo.find_git_version.should be_nil
 
+    # Non-tagged commit
     File.write("file.txt", "foo")
     `git add file.txt`
     `git commit -m 'Initial commit' --no-gpg-sign`
-    ProjectInfo.find_git_version.should be_nil
+    ProjectInfo.find_git_version.should eq "master"
+
+    # Non-tagged commit, dirty workdir
+    File.write("file.txt", "bar")
+    ProjectInfo.find_git_version.should eq "master-dev"
+
+    `git checkout -- .`
 
+    # Tagged commit
     `git tag v0.1.0`
     ProjectInfo.find_git_version.should eq "0.1.0"
 
+    # Tagged commit, dirty workdir
     File.write("file.txt", "bar")
-    ProjectInfo.find_git_version.should be_nil
+    ProjectInfo.find_git_version.should eq "0.1.0-dev"
 
+    # Tagged commit, dirty index
     `git add file.txt`
-    ProjectInfo.find_git_version.should be_nil
+    ProjectInfo.find_git_version.should eq "0.1.0-dev"
 
     `git reset --hard v0.1.0`
     ProjectInfo.find_git_version.should eq "0.1.0"
 
+    # Multiple tags
     `git tag v0.2.0`
-    ProjectInfo.find_git_version.should be_nil
+    ProjectInfo.find_git_version.should eq "master"
+
+    # Other branch
+    `git checkout -b foo`
+    ProjectInfo.find_git_version.should eq "foo"
   end
 
   describe ".read_shard_properties" do
diff --git a/src/compiler/crystal/tools/doc/project_info.cr b/src/compiler/crystal/tools/doc/project_info.cr
index 4f95ecd01060..6744253f4966 100644
--- a/src/compiler/crystal/tools/doc/project_info.cr
+++ b/src/compiler/crystal/tools/doc/project_info.cr
@@ -17,14 +17,30 @@ module Crystal::Doc
     end
 
     def self.find_git_version
+      if ref = git_ref
+        case git_clean?
+        when Nil
+        when true
+          ref
+        when false
+          "#{ref}-dev"
+        end
+      end
+    end
+
+    def self.git_clean?
       # Use git to determine if index and working directory are clean
       io = IO::Memory.new
       status = Process.run("git", ["status", "--porcelain"], output: io)
       # If clean, output of `git status --porcelain` is empty. Still need to check
       # the status code, to make sure empty doesn't mean error.
+      return unless status.success?
       io.rewind
-      return unless status.success? && io.bytesize == 0
+      io.bytesize == 0
+    end
 
+    def self.git_ref
+      io = IO::Memory.new
       # Check if current HEAD is tagged
       status = Process.run("git", ["tag", "--points-at", "HEAD"], output: io)
       return unless status.success?
@@ -35,6 +51,13 @@ module Crystal::Doc
       if versions.size == 1
         return versions.first.byte_slice(1)
       end
+
+      # Otherwise, return current branch name
+      io.clear
+      status = Process.run("git", ["rev-parse", "--abbrev-ref", "HEAD"], output: io)
+      return unless status.success?
+
+      io.to_s.strip.presence
     end
 
     def self.read_shard_properties