diff --git a/Dockerfile b/Dockerfile
index a0a209e1..b1f4a2bc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -48,9 +48,6 @@ RUN echo $VERSION > VERSION
 
 # Set paths for when running in a container
 ENV POSTAL_CONFIG_FILE_PATH=/config/postal.yml
-ENV POSTAL_SIGNING_KEY_PATH=/config/signing.key
-ENV SMTP_SERVER_TLS_CERTIFICATE_PATH=/config/smtp.cert
-ENV SMTP_SERVER_TLS_PRIVATE_KEY_PATH=/config/smtp.key
 
 # Set the CMD
 ENTRYPOINT [ "/docker-entrypoint.sh" ]
diff --git a/Gemfile b/Gemfile
index 46eca03a..c3efa379 100644
--- a/Gemfile
+++ b/Gemfile
@@ -16,7 +16,7 @@ gem "hashie"
 gem "highline", require: false
 gem "kaminari"
 gem "klogger-logger"
-gem "konfig-config", "~> 2.0"
+gem "konfig-config", "~> 3.0"
 gem "mail"
 gem "moonrope"
 gem "mysql2"
diff --git a/Gemfile.lock b/Gemfile.lock
index 172a5225..c6b997b3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -149,7 +149,7 @@ GEM
       concurrent-ruby (>= 1.0, < 2.0)
       json
       rouge (>= 3.30, < 5.0)
-    konfig-config (2.1.1)
+    konfig-config (3.0.0)
       hashie
     loofah (2.22.0)
       crass (~> 1.0.2)
@@ -353,7 +353,7 @@ DEPENDENCIES
   jquery-rails
   kaminari
   klogger-logger
-  konfig-config (~> 2.0)
+  konfig-config (~> 3.0)
   mail
   moonrope
   mysql2
diff --git a/lib/postal/config_schema.rb b/lib/postal/config_schema.rb
index 42a661a4..45a55086 100644
--- a/lib/postal/config_schema.rb
+++ b/lib/postal/config_schema.rb
@@ -68,7 +68,8 @@ module Postal
 
       string :signing_key_path do
         description "Path to the private key used for signing"
-        default "config/postal/signing.key"
+        default "$config-file-root/signing.key"
+        transform { |v| Postal.substitute_config_file_root(v) }
       end
 
       string :smtp_relays do
@@ -253,12 +254,14 @@ module Postal
 
       string :tls_certificate_path do
         description "The path to the SMTP server's TLS certificate"
-        default "config/postal/smtp.cert"
+        default "$config-file-root/smtp.cert"
+        transform { |v| Postal.substitute_config_file_root(v) }
       end
 
       string :tls_private_key_path do
         description "The path to the SMTP server's TLS private key"
-        default "config/postal/smtp.key"
+        default "$config-file-root/smtp.key"
+        transform { |v| Postal.substitute_config_file_root(v) }
       end
 
       string :tls_ciphers do
@@ -502,4 +505,14 @@ module Postal
     end
   end
 
+  class << self
+
+    def substitute_config_file_root(string)
+      return if string.nil?
+
+      string.gsub(/\$config-file-root/i, File.dirname(Postal.config_file_path))
+    end
+
+  end
+
 end
diff --git a/spec/lib/postal/legacy_config_source_spec.rb b/spec/lib/postal/legacy_config_source_spec.rb
index a3b69550..0032a3ba 100644
--- a/spec/lib/postal/legacy_config_source_spec.rb
+++ b/spec/lib/postal/legacy_config_source_spec.rb
@@ -17,7 +17,9 @@ module Postal
       # by the schema itself. Otherwise, we might see a value returned that
       # looks correct but is actually the default rather than the value from
       # config file.
-      allow_any_instance_of(Konfig::SchemaAttribute).to receive(:default).and_return(nil)
+      allow_any_instance_of(Konfig::SchemaAttribute).to receive(:default) do |a|
+        a.array? ? [] : nil
+      end
     end
 
     let(:source) { described_class.new(SOURCE_CONFIG) }