diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc2902a1..a7702952 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,7 @@ version is 3.10.
 - Add an "Account closed." confirmation message after closing an account
 - Add monthly uptime percentage display in Check Details page (#773)
 - Increase the precision of calculated downtime duration in check's details and reports
+- Increase bottom margin for modal windows to work around Mobile Safari issue (#899)
 
 ### Bug Fixes
 - Fix "senddeletionnotices" to recognize "Supporter" subscriptions
diff --git a/static/css/bootstrap.css b/static/css/bootstrap.css
index 04ee98e0..80bdacf0 100644
--- a/static/css/bootstrap.css
+++ b/static/css/bootstrap.css
@@ -4310,7 +4310,7 @@ button.close {
 .modal-dialog {
   position: relative;
   width: auto;
-  margin: 10px;
+  margin: 10px 10px 60px 10px;
 }
 .modal-content {
   position: relative;
diff --git a/stuff/bootstrap/modals.less b/stuff/bootstrap/modals.less
index 2fe8e56f..315dbe8f 100644
--- a/stuff/bootstrap/modals.less
+++ b/stuff/bootstrap/modals.less
@@ -44,7 +44,9 @@
 .modal-dialog {
   position: relative;
   width: auto;
-  margin: 10px;
+  // Use 60px bottom margin to prevent Mobile Safari's nav bar from interfering
+  // See: https://github.com/healthchecks/healthchecks/pull/899
+  margin: 10px 10px 60px 10px;
 }
 
 // Actual modal