diff --git a/Cargo.lock b/Cargo.lock
index fcab1aa7..6e3973fc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -10,15 +10,15 @@ dependencies = [
 
 [[package]]
 name = "ammonia"
-version = "2.1.2"
+version = "3.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "html5ever 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "html5ever 0.24.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "maplit 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "url 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -420,12 +420,12 @@ dependencies = [
 
 [[package]]
 name = "html5ever"
-version = "0.23.0"
+version = "0.24.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "mac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "markup5ever 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "markup5ever 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 0.4.30 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 0.15.34 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -612,7 +612,7 @@ dependencies = [
 
 [[package]]
 name = "markup5ever"
-version = "0.8.1"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -635,7 +635,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "mdbook"
 version = "0.3.1"
 dependencies = [
- "ammonia 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ammonia 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "elasticlunr-rs 2.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1655,7 +1655,7 @@ dependencies = [
 
 [metadata]
 "checksum aho-corasick 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e6f484ae0c99fec2e858eb6134949117399f222608d84cadb3f58c1f97c2364c"
-"checksum ammonia 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "384d704f242a0a9faf793fff775a0be6ab9aa27edabffa097331d73779142520"
+"checksum ammonia 3.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9e266e1f4be5ffa05309f650e2586fe1d3ae6034eb24025a7ae1dfecc330823a"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
 "checksum autocfg 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "0e49efa51329a5fd37e7c79db4621af617cd4e3e5bc224939808d076077077bf"
@@ -1703,7 +1703,7 @@ dependencies = [
 "checksum hashbrown 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e1de41fb8dba9714efd92241565cdff73f78508c95697dd56787d3cba27e2353"
 "checksum heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "20564e78d53d2bb135c343b3f47714a56af2061f1c928fdb541dc7b9fdd94205"
 "checksum html5ever 0.18.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a49d5001dd1bddf042ea41ed4e0a671d50b1bf187e66b349d7ec613bdce4ad90"
-"checksum html5ever 0.23.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5ce65ac8028cf5a287a7dbf6c4e0a6cf2dcf022ed5b167a81bae66ebf599a8b7"
+"checksum html5ever 0.24.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2a62c2cb2d34faa27dea3f2380ee8b06b8ff9c18e1cd5358e1da20b51089f4f1"
 "checksum httparse 1.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e8734b0cfd3bc3e101ec59100e101c2eecd19282202e87808b3037b442777a83"
 "checksum humantime 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3ca7e5f2e110db35f93b837c81797f3714500b81d517bf20c431b16d3ca4f114"
 "checksum hyper 0.10.16 (registry+https://github.com/rust-lang/crates.io-index)" = "0a0652d9a2609a968c14be1a9ea00bf4b1d64e2e1f53a1b51b6fff3a6e829273"
@@ -1727,7 +1727,7 @@ dependencies = [
 "checksum mac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
 "checksum maplit 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "08cbb6b4fef96b6d77bfc40ec491b1690c779e77b05cd9f07f787ed376fd4c43"
 "checksum markup5ever 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "ff834ac7123c6a37826747e5ca09db41fd7a83126792021c2e636ad174bb77d3"
-"checksum markup5ever 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f1af46a727284117e09780d05038b1ce6fc9c76cc6df183c3dae5a8955a25e21"
+"checksum markup5ever 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "65381d9d47506b8592b97c4efd936afcf673b09b059f2bef39c7211ee78b9d03"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 "checksum memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2efc7bc57c883d4a4d6e3246905283d8dae951bb3bd32f49d6ef297f546e1c39"
 "checksum mime 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "ba626b8a6de5da682e1caa06bdb42a335aee5a84db8e5046a3e8ab17ba0a3ae0"
diff --git a/Cargo.toml b/Cargo.toml
index 95238c75..bf429b2f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -46,7 +46,7 @@ ws = { version = "0.8", optional = true}
 
 # Search feature
 elasticlunr-rs = { version = "2.3", optional = true, default-features = false }
-ammonia = { version = "2.1.2", optional = true }
+ammonia = { version = "3", optional = true }
 
 [dev-dependencies]
 select = "0.4"