diff --git a/lib/jekyll/commands/doctor.rb b/lib/jekyll/commands/doctor.rb
index a29cbf7e..953c2623 100644
--- a/lib/jekyll/commands/doctor.rb
+++ b/lib/jekyll/commands/doctor.rb
@@ -51,12 +51,10 @@ module Jekyll
           urls = {}
           urls = collect_urls(urls, site.pages, site.dest)
           urls = collect_urls(urls, site.posts.docs, site.dest)
-          urls.each do |url, paths|
-            if paths.size > 1
-              conflicting_urls = true
-              Jekyll.logger.warn "Conflict:", "The URL '#{url}' is the destination" \
-                " for the following pages: #{paths.join(", ")}"
-            end
+          urls.select { |_, p| p.size > 1 }.each do |url, paths|
+            conflicting_urls = true
+            Jekyll.logger.warn "Conflict:", "The URL '#{url}' is the destination" \
+              " for the following pages: #{paths.join(", ")}"
           end
           conflicting_urls
         end
@@ -80,13 +78,11 @@ module Jekyll
         def urls_only_differ_by_case(site)
           urls_only_differ_by_case = false
           urls = case_insensitive_urls(site.pages + site.docs_to_write, site.dest)
-          urls.each do |case_insensitive_url, real_urls|
-            if real_urls.uniq.size > 1
-              urls_only_differ_by_case = true
-              Jekyll.logger.warn "Warning:", "The following URLs only differ" \
-                " by case. On a case-insensitive file system one of the URLs" \
-                " will be overwritten by the other: #{real_urls.join(", ")}"
-            end
+          urls.select { |_, p| p.size > 1 }.each do |_, real_urls|
+            urls_only_differ_by_case = true
+            Jekyll.logger.warn "Warning:", "The following URLs only differ" \
+              " by case. On a case-insensitive file system one of the URLs" \
+              " will be overwritten by the other: #{real_urls.join(", ")}"
           end
           urls_only_differ_by_case
         end
diff --git a/lib/jekyll/tags/post_url.rb b/lib/jekyll/tags/post_url.rb
index 2da26ec0..723eafd7 100644
--- a/lib/jekyll/tags/post_url.rb
+++ b/lib/jekyll/tags/post_url.rb
@@ -59,23 +59,21 @@ eos
       def render(context)
         site = context.registers[:site]
 
-        site.posts.docs.each do |p|
-          if @post == p
-            return p.url
-          end
+        post = site.posts.docs.find { |p| @post == p }
+        if post
+          return post.url
         end
 
         # New matching method did not match, fall back to old method
         # with deprecation warning if this matches
 
-        site.posts.docs.each do |p|
-          if @post.deprecated_equality p
-            Jekyll::Deprecator.deprecation_message "A call to '{{ post_url #{@post.name} }}' did not match " \
-              "a post using the new matching method of checking name " \
-              "(path-date-slug) equality. Please make sure that you " \
-              "change this tag to match the post's name exactly."
-            return p.url
-          end
+        post = site.posts.docs.find { |p| @post.deprecated_equality p }
+        if post
+          Jekyll::Deprecator.deprecation_message "A call to '{{ post_url #{@post.name} }}' did not match " \
+            "a post using the new matching method of checking name " \
+            "(path-date-slug) equality. Please make sure that you " \
+            "change this tag to match the post's name exactly."
+          return post.url
         end
 
         raise ArgumentError.new <<-eos