diff --git a/Gemfile b/Gemfile
index 979606871f06e6cfcddaa614eb8c5acaeb64e05c..617c30c982bede6707a50dfbbd9e35253cffa30e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -28,7 +28,7 @@ gem "devise_lastseenable", "0.0.6"
 
 # Captcha
 
-gem "simple_captcha2", "0.4.0", require: "simple_captcha"
+gem "simple_captcha2", "0.4.3", require: "simple_captcha"
 
 # Background processing
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 76b23855d505bdf8041a956005181ad192650da9..e2b919c3e5c2d1851f3a556352c5e23609273ba6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -668,7 +668,7 @@ GEM
       rufus-scheduler (>= 2.0.24)
       sidekiq (>= 4.2.1)
     sigar (0.7.3)
-    simple_captcha2 (0.4.0)
+    simple_captcha2 (0.4.3)
       rails (>= 4.1)
     simple_oauth (0.3.1)
     simplecov (0.12.0)
@@ -903,7 +903,7 @@ DEPENDENCIES
   shoulda-matchers (= 3.1.1)
   sidekiq (= 4.2.9)
   sidekiq-cron (= 0.4.5)
-  simple_captcha2 (= 0.4.0)
+  simple_captcha2 (= 0.4.3)
   simplecov (= 0.12.0)
   sinon-rails (= 1.15.0)
   spring (= 2.0.0)