diff --git a/DESCRIPTION b/DESCRIPTION
index c16582c..2dfe0be 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -20,7 +20,7 @@ Suggests:
     curl,
     testthat,
     xml2
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.2
 Roxygen: list(markdown = TRUE)
 Language: en-US
 Encoding: UTF-8
diff --git a/NEWS b/NEWS
index 59be9da..42c3e65 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,6 @@
-1.9.3
+1.9.4
   - Apply upstream PR https://github.com/github/cmark-gfm/pull/362
+  - Require double-tilde `~~` for the strikethrough extension, for consistency with Pandoc's Markdown
 
 1.9.1
   - Update libcmark-gfm to 0.29.0.gfm.13
diff --git a/R/extensions.R b/R/extensions.R
index 25fa328..64b4a2a 100644
--- a/R/extensions.R
+++ b/R/extensions.R
@@ -6,7 +6,7 @@
 #' Currently the following extensions are supported:
 #'
 #'  - **table** support rendering of tables: [gfm-spec section 4.10](https://github.github.com/gfm/#tables-extension-)
-#'  - **strikethrough** via `~sometext~` syntax: [gfm-spec section 6.5](https://github.github.com/gfm/#strikethrough-extension-)
+#'  - **strikethrough** via `~~sometext~~` syntax: [gfm-spec section 6.5](https://github.github.com/gfm/#strikethrough-extension-)
 #'  - **autolink** automatically turn URLs into hyperlinks: [gfm-spec section 6.9](https://github.github.com/gfm/#autolinks-extension-)
 #'  - **tagfilter** blacklist html tags: `title` `textarea` `style` `xmp` `iframe`
 #' `noembed` `noframes` `script` `plaintext`: [gfm-spec section 6.11](https://github.github.com/gfm/#disallowed-raw-html-extension-)
diff --git a/man/extensions.Rd b/man/extensions.Rd
index 9751016..33937ae 100644
--- a/man/extensions.Rd
+++ b/man/extensions.Rd
@@ -15,7 +15,7 @@ features which are not (yet) in the official commonmark spec.
 Currently the following extensions are supported:
 \itemize{
 \item \strong{table} support rendering of tables: \href{https://github.github.com/gfm/#tables-extension-}{gfm-spec section 4.10}
-\item \strong{strikethrough} via \verb{~sometext~} syntax: \href{https://github.github.com/gfm/#strikethrough-extension-}{gfm-spec section 6.5}
+\item \strong{strikethrough} via \verb{~~sometext~~} syntax: \href{https://github.github.com/gfm/#strikethrough-extension-}{gfm-spec section 6.5}
 \item \strong{autolink} automatically turn URLs into hyperlinks: \href{https://github.github.com/gfm/#autolinks-extension-}{gfm-spec section 6.9}
 \item \strong{tagfilter} blacklist html tags: \code{title} \code{textarea} \code{style} \code{xmp} \code{iframe}
 \code{noembed} \code{noframes} \code{script} \code{plaintext}: \href{https://github.github.com/gfm/#disallowed-raw-html-extension-}{gfm-spec section 6.11}
diff --git a/tests/testthat/test-extensions.R b/tests/testthat/test-extensions.R
index fa922fe..f4a9488 100644
--- a/tests/testthat/test-extensions.R
+++ b/tests/testthat/test-extensions.R
@@ -47,3 +47,9 @@ test_that("embedded images do not get filtered", {
   expect_equal(md, markdown_html(md))
   expect_equal(md, markdown_commonmark(md))
 })
+
+test_that("strikethrough", {
+  md <- "~Hello~ ~~world~~!"
+  expect_equal(markdown_html(md), "<p>~Hello~ ~~world~~!</p>\n")
+  expect_equal(markdown_html(md, extensions = "strikethrough"), "<p>~Hello~ <del>world</del>!</p>\n")
+})