diff --git a/ftplugin/markdown.vim b/ftplugin/markdown.vim
index 5e402269..812583a8 100644
--- a/ftplugin/markdown.vim
+++ b/ftplugin/markdown.vim
@@ -48,12 +48,12 @@
 " For each level, contains the regexp that matches at that level only.
 "
 let s:levelRegexpDict = {
-    \ 1: '\v^(#[^#]@=|.+\n\=+$)',
-    \ 2: '\v^(##[^#]@=|.+\n-+$)',
-    \ 3: '\v^###[^#]@=',
-    \ 4: '\v^####[^#]@=',
-    \ 5: '\v^#####[^#]@=',
-    \ 6: '\v^######[^#]@='
+    \ 1: '\v^(#\_s@=|.+\n\=+$)',
+    \ 2: '\v^(##\_s@=|.+\n-+$)',
+    \ 3: '\v^###\_s@=',
+    \ 4: '\v^####\_s@=',
+    \ 5: '\v^#####\_s@=',
+    \ 6: '\v^######\_s@='
 \ }
 
 " Maches any header level of any type.
@@ -61,7 +61,7 @@ let s:levelRegexpDict = {
 " This could be deduced from `s:levelRegexpDict`, but it is more
 " efficient to have a single regexp for this.
 "
-let s:headersRegexp = '\v^(#|.+\n(\=+|-+)$)'
+let s:headersRegexp = '\v^(#{1,6}\_s|.+\n(\=+|-+)$)'
 
 " Returns the line number of the first header before `line`, called the
 " current header.
diff --git a/test/header-decrease.vader b/test/header-decrease.vader
new file mode 100644
index 00000000..39510d3c
--- /dev/null
+++ b/test/header-decrease.vader
@@ -0,0 +1,143 @@
+Given markdown;
+# a
+
+## b
+
+### c
+
+#### d
+
+##### e
+
+Execute (HeaderIncrease without forbidden level):
+  :HeaderIncrease
+
+Expect (increase level of all headers):
+  ## a
+
+  ### b
+
+  #### c
+
+  ##### d
+
+  ###### e
+
+Given markdown;
+# a
+
+###### b
+
+Execute (HeaderIncrease with forbidden level):
+  :HeaderIncrease
+
+Expect (no changes):
+  # a
+
+  ###### b
+
+Given markdown;
+## a
+
+### b
+
+#### c
+
+##### d
+
+###### e
+
+Execute (HeaderDecrease without forbidden level):
+  :HeaderDecrease
+
+Expect (decrease level of all headers):
+  # a
+
+  ## b
+
+  ### c
+
+  #### d
+
+  ##### e
+
+Given markdown;
+# a
+
+## b
+
+### c
+
+#### d
+
+##### e
+
+###### f
+
+Execute (HeaderDecrease with forbidden level):
+  :HeaderDecrease
+
+Expect (no changes):
+  # a
+
+  ## b
+
+  ### c
+
+  #### d
+
+  ##### e
+
+  ###### f
+
+Given markdown;
+## a
+
+##hashtag
+
+Execute (HeaderDecrease with hashtag):
+  :HeaderDecrease
+
+Expect (hashtags are not affected):
+  # a
+
+  ##hashtag
+
+Given markdown;
+# a
+
+#hashtag
+
+Execute (HeaderIncrease with hashtag):
+  :HeaderIncrease
+
+Expect (hashtags are not affected):
+  ## a
+
+  #hashtag
+
+Given markdown;
+#
+
+##
+
+Execute (HeaderIncrease with empty atx headings):
+  :HeaderIncrease
+
+Expect (increase level of all headers):
+  ##
+
+  ###
+
+Given markdown;
+##
+
+###
+
+Execute (HeaderDecrease with empty atx headings):
+  :HeaderDecrease
+
+Expect (decrease level of all headers):
+  #
+
+  ##
diff --git a/test/map.vader b/test/map.vader
index 57fe6190..7c9304bd 100644
--- a/test/map.vader
+++ b/test/map.vader
@@ -94,6 +94,8 @@ Given markdown;
 
 b
 
+#ignore
+
 # c
 
 d
@@ -101,7 +103,7 @@ d
 Execute (]] same level):
   AssertEqual line('.'), 1
   normal ]]
-  AssertEqual line('.'), 5
+  AssertEqual line('.'), 7
   normal [[
   AssertEqual line('.'), 1
 
@@ -110,6 +112,8 @@ Given markdown;
 
 b
 
+##ignore
+
 ## c
 
 d
@@ -117,7 +121,7 @@ d
 Execute (]] different levels level):
   AssertEqual line('.'), 1
   normal ]]
-  AssertEqual line('.'), 5
+  AssertEqual line('.'), 7
   normal [[
   AssertEqual line('.'), 1
 
@@ -126,6 +130,8 @@ Given markdown;
 
 b
 
+#ignore
+
 ## c
 
 d
@@ -137,7 +143,7 @@ f
 Execute (][ different levels level):
   AssertEqual line('.'), 1
   normal ][
-  AssertEqual line('.'), 9
+  AssertEqual line('.'), 11
   normal []
   AssertEqual line('.'), 1
 
@@ -151,3 +157,23 @@ Execute (]h):
   AssertEqual line('.'), 3
   normal ]h
   AssertEqual line('.'), 1
+
+Given markdown;
+#
+
+##
+
+#
+
+##
+
+Execute (]] empty atx heading):
+  AssertEqual line('.'), 1
+  normal ]]
+  AssertEqual line('.'), 3
+  normal [[
+  AssertEqual line('.'), 1
+  normal ][
+  AssertEqual line('.'), 5
+  normal []
+  AssertEqual line('.'), 1
diff --git a/test/toc.vader b/test/toc.vader
index 51269526..545c5419 100644
--- a/test/toc.vader
+++ b/test/toc.vader
@@ -138,14 +138,11 @@ Execute (Toc multiple headers):
 
 Expect (multiple headers):
   h1 space
-  h1 nospace
   h1 2 spaces
   h1 trailing hash
     h2 space
-    h2 nospace
     h2 trailing hash
       h3 space
-      h3 nospace
       h3 trailing hash
         h4
           h5