diff --git a/debian/control b/debian/control
index 2e487e6..e5f130c 100644
--- a/debian/control
+++ b/debian/control
@@ -12,6 +12,7 @@
  flex,
  libicu-dev,
  libssl-dev,
+ locales-all,
  postgresql-all (>= 217~),
 Standards-Version: 4.5.0
 Homepage: https://github.com/orafce/orafce
diff --git a/debian/control.in b/debian/control.in
index 1c8846b..de544de 100644
--- a/debian/control.in
+++ b/debian/control.in
@@ -12,6 +12,7 @@
  flex,
  libicu-dev,
  libssl-dev,
+ locales-all,
  postgresql-all (>= 217~),
 Standards-Version: 4.5.0
 Homepage: https://github.com/orafce/orafce
diff --git a/debian/rules b/debian/rules
index f4a5386..1d1d0ca 100755
--- a/debian/rules
+++ b/debian/rules
@@ -1,7 +1,7 @@
 #!/usr/bin/make -f
 
 # testsuite needs English and UTF-8
-export LC_ALL=C.UTF-8
+export LANG=en_US.utf8
 
 %:
 	dh $@ --with pgxs_loop
diff --git a/debian/tests/control b/debian/tests/control
index 8af9907..edc47ab 100644
--- a/debian/tests/control
+++ b/debian/tests/control
@@ -1,3 +1,3 @@
-Depends: @, make
+Depends: @, locales-all, make
 Tests: installcheck
 Restrictions: allow-stderr
diff --git a/debian/tests/installcheck b/debian/tests/installcheck
index b9a2ef8..10a32bb 100755
--- a/debian/tests/installcheck
+++ b/debian/tests/installcheck
@@ -1,4 +1,6 @@
 #!/bin/sh
 
 # to_multi_byte needs English, and UTF-8
-LC_ALL=C.UTF-8 pg_buildext installcheck
+export LANG=en_US.utf8
+
+pg_buildext installcheck