diff --git a/lib/importmap/npm.rb b/lib/importmap/npm.rb
index 921ac41..b47f39e 100644
--- a/lib/importmap/npm.rb
+++ b/lib/importmap/npm.rb
@@ -48,8 +48,8 @@ def packages_with_versions
     # We cannot use the name after "pin" because some dependencies are loaded from inside packages
     # Eg. pin "buffer", to: "https://ga.jspm.io/npm:@jspm/core@2.0.0-beta.19/nodelibs/browser/buffer.js"
 
-    importmap.scan(/^pin .*(?<=npm:|npm\/|skypack\.dev\/|unpkg\.com\/)(.*)(?=@\d+\.\d+\.\d+)@(\d+\.\d+\.\d+(?:[^\/\s"]*)).*$/) |
-      importmap.scan(/^pin "([^"]*)".* #.*@(\d+\.\d+\.\d+(?:[^\s]*)).*$/)
+    importmap.scan(/^pin .*(?<=npm:|npm\/|skypack\.dev\/|unpkg\.com\/)(.*)(?=@\d+\.\d+\.\d+)@(\d+\.\d+\.\d+(?:[^\/\s["']]*)).*$/) |
+      importmap.scan(/^pin ["']([^["']]*)["'].* #.*@(\d+\.\d+\.\d+(?:[^\s]*)).*$/)
   end
 
   private
diff --git a/test/fixtures/files/single_quote_outdated_import_map.rb b/test/fixtures/files/single_quote_outdated_import_map.rb
new file mode 100644
index 0000000..fd9942d
--- /dev/null
+++ b/test/fixtures/files/single_quote_outdated_import_map.rb
@@ -0,0 +1 @@
+pin 'md5', to: 'https://cdn.skypack.dev/md5@2.2.0', preload: true
diff --git a/test/fixtures/files/single_quote_outdated_import_map_without_cdn.rb b/test/fixtures/files/single_quote_outdated_import_map_without_cdn.rb
new file mode 100644
index 0000000..56b2092
--- /dev/null
+++ b/test/fixtures/files/single_quote_outdated_import_map_without_cdn.rb
@@ -0,0 +1 @@
+pin 'md5', preload: true #@2.2.0
diff --git a/test/npm_test.rb b/test/npm_test.rb
index 4c2a956..fd6f122 100644
--- a/test/npm_test.rb
+++ b/test/npm_test.rb
@@ -18,6 +18,34 @@ class Importmap::NpmTest < ActiveSupport::TestCase
     end
   end
 
+  test "successful outdated packages using single-quotes with mock" do
+    npm = Importmap::Npm.new(file_fixture("single_quote_outdated_import_map.rb"))
+    response = { "dist-tags" => { "latest" => '2.3.0' } }.to_json
+
+    npm.stub(:get_json, response) do
+      outdated_packages = npm.outdated_packages
+
+      assert_equal(1, outdated_packages.size)
+      assert_equal('md5', outdated_packages[0].name)
+      assert_equal('2.2.0', outdated_packages[0].current_version)
+      assert_equal('2.3.0', outdated_packages[0].latest_version)
+    end
+  end
+
+  test "successful outdated packages using single-quotes and without CDN with mock" do
+    npm = Importmap::Npm.new(file_fixture("single_quote_outdated_import_map_without_cdn.rb"))
+    response = { "dist-tags" => { "latest" => '2.3.0' } }.to_json
+
+    npm.stub(:get_json, response) do
+      outdated_packages = npm.outdated_packages
+
+      assert_equal(1, outdated_packages.size)
+      assert_equal('md5', outdated_packages[0].name)
+      assert_equal('2.2.0', outdated_packages[0].current_version)
+      assert_equal('2.3.0', outdated_packages[0].latest_version)
+    end
+  end
+
   test "missing outdated packages with mock" do
     response = { "error" => "Not found" }.to_json