diff --git a/CHANGELOG.md b/CHANGELOG.md
index dde59cd..70808c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- Remove redundant Mercurial install step (#1111).
 - Remove support for the Cedar-14 stack (#1110).
 
 ## v184 (2020-10-21)
diff --git a/Makefile b/Makefile
index 48b3fef..84668a7 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ STACK_IMAGE_TAG := heroku/$(subst -,:,$(STACK))-build
 
 check:
 	@shellcheck -x bin/compile bin/detect bin/release bin/test-compile bin/utils bin/warnings bin/default_pythons
-	@shellcheck -x bin/steps/collectstatic bin/steps/eggpath-fix  bin/steps/eggpath-fix2 bin/steps/gdal bin/steps/geo-libs bin/steps/mercurial bin/steps/nltk bin/steps/pip-install bin/steps/pip-uninstall bin/steps/pipenv bin/steps/pipenv-python-version bin/steps/python
+	@shellcheck -x bin/steps/collectstatic bin/steps/eggpath-fix  bin/steps/eggpath-fix2 bin/steps/gdal bin/steps/geo-libs bin/steps/nltk bin/steps/pip-install bin/steps/pip-uninstall bin/steps/pipenv bin/steps/pipenv-python-version bin/steps/python
 	@shellcheck -x bin/steps/hooks/*
 
 test:
diff --git a/bin/compile b/bin/compile
index 1ba32a7..150dc83 100755
--- a/bin/compile
+++ b/bin/compile
@@ -263,12 +263,6 @@ fi
 # shellcheck source=bin/steps/eggpath-fix
 source "$BIN_DIR/steps/eggpath-fix"
 
-# Mercurial support.
-# If a customer appears to be using mercurial for dependency resolution, we install it first.
-# Note: this only applies to pip, not pipenv. This can likely be removed, over time. Measure it first.
-# shellcheck source=bin/steps/mercurial
-source "$BIN_DIR/steps/mercurial"
-
 # Support for Geo libraries. This is deprecated functionality.
 # It is undocumented.
 # shellcheck source=bin/steps/geo-libs
diff --git a/bin/steps/mercurial b/bin/steps/mercurial
deleted file mode 100755
index c36cb9a..0000000
--- a/bin/steps/mercurial
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/usr/bin/env bash
-
-# Install Mercurial if it appears to be required.
-if [[ -f "requirements.txt" ]]; then
-	if (grep -Fiq "hg+" requirements.txt) then
-		/app/.heroku/python/bin/pip install  mercurial | cleanup | indent
-		mcount "steps.mercurial"
-	fi
-fi
diff --git a/test/fixtures/requirements-mercurial/requirements.txt b/test/fixtures/requirements-mercurial/requirements.txt
new file mode 100644
index 0000000..08ee098
--- /dev/null
+++ b/test/fixtures/requirements-mercurial/requirements.txt
@@ -0,0 +1 @@
+hg+https://www.mercurial-scm.org/repo/python-hglib/#egg=python-hglib
diff --git a/test/run-deps b/test/run-deps
index beb87f6..4af435f 100755
--- a/test/run-deps
+++ b/test/run-deps
@@ -74,6 +74,12 @@ testPylibmc() {
   assertCapturedSuccess
 }
 
+testMercurial() {
+  compile "requirements-mercurial"
+  assertCaptured "Cloning hg"
+  assertCapturedSuccess
+}
+
 pushd $(dirname 0) >/dev/null
 popd >/dev/null