diff --git a/tests/data/test1034 b/tests/data/test1034
index d926e82ba7..968c96d250 100644
--- a/tests/data/test1034
+++ b/tests/data/test1034
@@ -29,8 +29,8 @@ proxy
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 HTTP over proxy with malformatted IDN host name
diff --git a/tests/data/test1035 b/tests/data/test1035
index fc5f1c28f2..bdd85256d2 100644
--- a/tests/data/test1035
+++ b/tests/data/test1035
@@ -27,8 +27,8 @@ proxy
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 HTTP over proxy with too long IDN host name
diff --git a/tests/data/test1448 b/tests/data/test1448
index 96d64b85a5..0b57af2e27 100644
--- a/tests/data/test1448
+++ b/tests/data/test1448
@@ -43,8 +43,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 Redirect following to UTF-8 IDN host name
diff --git a/tests/data/test1560 b/tests/data/test1560
index 42da17176d..92b08cdeda 100644
--- a/tests/data/test1560
+++ b/tests/data/test1560
@@ -13,8 +13,8 @@ urlapi
 none
 </server>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <features>
 file
diff --git a/tests/data/test165 b/tests/data/test165
index 0b5cfd2346..7a61f10aad 100644
--- a/tests/data/test165
+++ b/tests/data/test165
@@ -33,8 +33,8 @@ proxy
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 HTTP over proxy with IDN host name
diff --git a/tests/data/test2046 b/tests/data/test2046
index cf25d0c57b..85c48e9183 100644
--- a/tests/data/test2046
+++ b/tests/data/test2046
@@ -43,8 +43,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 Connection reuse with IDN host name
diff --git a/tests/data/test2047 b/tests/data/test2047
index c32e6aabc7..fdc3fcc9f1 100644
--- a/tests/data/test2047
+++ b/tests/data/test2047
@@ -44,8 +44,8 @@ proxy
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 Connection reuse with IDN host name over HTTP proxy
diff --git a/tests/data/test955 b/tests/data/test955
index 817b47a67e..db4db3a8c2 100644
--- a/tests/data/test955
+++ b/tests/data/test955
@@ -24,8 +24,8 @@ smtp
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based sender (local part only)
diff --git a/tests/data/test956 b/tests/data/test956
index 4546f2ee61..14c37e7683 100644
--- a/tests/data/test956
+++ b/tests/data/test956
@@ -21,8 +21,8 @@ smtp
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based recipient (local part only)
diff --git a/tests/data/test957 b/tests/data/test957
index 9548627b98..3edb850a8b 100644
--- a/tests/data/test957
+++ b/tests/data/test957
@@ -22,8 +22,8 @@ smtp
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP VRFY without SMTPUTF8 support - UTF-8 recipient (local part only)
diff --git a/tests/data/test958 b/tests/data/test958
index f1006a0a66..71a74b2527 100644
--- a/tests/data/test958
+++ b/tests/data/test958
@@ -22,8 +22,8 @@ smtp
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP external VRFY without SMTPUTF8 - UTF-8 recipient (local part only)
diff --git a/tests/data/test959 b/tests/data/test959
index 2154600da2..e80dcc1cc9 100644
--- a/tests/data/test959
+++ b/tests/data/test959
@@ -25,8 +25,8 @@ smtp
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based sender (host part only)
diff --git a/tests/data/test960 b/tests/data/test960
index fb50a326b2..ec486ac0ad 100644
--- a/tests/data/test960
+++ b/tests/data/test960
@@ -22,8 +22,8 @@ smtp
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based recipient (host part only)
diff --git a/tests/data/test961 b/tests/data/test961
index 2068d8fc84..ceb3a4f764 100644
--- a/tests/data/test961
+++ b/tests/data/test961
@@ -23,8 +23,8 @@ smtp
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP external VRFY without SMTPUTF8 - UTF-8 recipient (host part only)
diff --git a/tests/data/test962 b/tests/data/test962
index 2573d72582..3f737b65ea 100644
--- a/tests/data/test962
+++ b/tests/data/test962
@@ -23,7 +23,7 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
+LC_ALL=C.UTF-8
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based sender (host part only)
diff --git a/tests/data/test963 b/tests/data/test963
index 5d3bae7b56..de34e58fea 100644
--- a/tests/data/test963
+++ b/tests/data/test963
@@ -23,8 +23,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP without SMTPUTF8 support (IDN) - UTF-8 recipient (host part only)
diff --git a/tests/data/test964 b/tests/data/test964
index 12c312eccd..08c499b4e4 100644
--- a/tests/data/test964
+++ b/tests/data/test964
@@ -24,8 +24,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP external VRFY without SMTPUTF8 (IDN) - UTF-8 recipient (host part)
diff --git a/tests/data/test965 b/tests/data/test965
index 0d29c09849..af86a41ac0 100644
--- a/tests/data/test965
+++ b/tests/data/test965
@@ -26,8 +26,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP with SMTPUTF8 support - UTF-8 based sender
diff --git a/tests/data/test966 b/tests/data/test966
index b642e19a9d..d44ddf8476 100644
--- a/tests/data/test966
+++ b/tests/data/test966
@@ -26,8 +26,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP with SMTPUTF8 support - UTF-8 based recipient
diff --git a/tests/data/test967 b/tests/data/test967
index f6e2e32382..0d422a28e6 100644
--- a/tests/data/test967
+++ b/tests/data/test967
@@ -30,8 +30,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP external VRFY with SMTPUTF8 support
diff --git a/tests/data/test968 b/tests/data/test968
index 8532c35e7d..c684113d29 100644
--- a/tests/data/test968
+++ b/tests/data/test968
@@ -27,8 +27,8 @@ IDN
 codeset-utf8
 </features>
 <setenv>
-LC_ALL=en_US.UTF-8
-LC_CTYPE=en_US.UTF-8
+LC_ALL=C.UTF-8
+PLACEHOLDER2
 </setenv>
 <name>
 SMTP VRFY with SMTPUTF8 support