diff --git a/tests/data/test1034 b/tests/data/test1034
index e2e04bd3d5..da70922c42 100644
--- a/tests/data/test1034
+++ b/tests/data/test1034
@@ -30,7 +30,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 HTTP over proxy with malformatted IDN host name
diff --git a/tests/data/test1035 b/tests/data/test1035
index 592a0369e6..c3cf7de7f5 100644
--- a/tests/data/test1035
+++ b/tests/data/test1035
@@ -28,7 +28,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 HTTP over proxy with too long IDN host name
diff --git a/tests/data/test1448 b/tests/data/test1448
index b3a22c86ab..9f75a04302 100644
--- a/tests/data/test1448
+++ b/tests/data/test1448
@@ -44,7 +44,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 Redirect following to UTF-8 IDN host name
diff --git a/tests/data/test1560 b/tests/data/test1560
index 1d2c30d2d2..e8334d5125 100644
--- a/tests/data/test1560
+++ b/tests/data/test1560
@@ -14,7 +14,7 @@ none
 </server>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <features>
 file
diff --git a/tests/data/test165 b/tests/data/test165
index 22aac8916b..ebd2e00550 100644
--- a/tests/data/test165
+++ b/tests/data/test165
@@ -34,7 +34,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 HTTP over proxy with IDN host name
diff --git a/tests/data/test2046 b/tests/data/test2046
index 7666277faa..53a9bfa045 100644
--- a/tests/data/test2046
+++ b/tests/data/test2046
@@ -44,7 +44,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 Connection reuse with IDN host name
diff --git a/tests/data/test2047 b/tests/data/test2047
index c2fc55c1b4..3e38bf67f8 100644
--- a/tests/data/test2047
+++ b/tests/data/test2047
@@ -45,7 +45,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 Connection reuse with IDN host name over HTTP proxy
diff --git a/tests/data/test955 b/tests/data/test955
index e7d2cc9a17..955212c8ab 100644
--- a/tests/data/test955
+++ b/tests/data/test955
@@ -25,7 +25,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based sender (local part only)
diff --git a/tests/data/test956 b/tests/data/test956
index 5d9a9f8936..92f098c306 100644
--- a/tests/data/test956
+++ b/tests/data/test956
@@ -22,7 +22,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based recipient (local part only)
diff --git a/tests/data/test957 b/tests/data/test957
index 8b3ebc8d47..70ed841fc6 100644
--- a/tests/data/test957
+++ b/tests/data/test957
@@ -23,7 +23,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP VRFY without SMTPUTF8 support - UTF-8 recipient (local part only)
diff --git a/tests/data/test958 b/tests/data/test958
index 15a23fb4c1..f5eb54f04e 100644
--- a/tests/data/test958
+++ b/tests/data/test958
@@ -23,7 +23,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP external VRFY without SMTPUTF8 - UTF-8 recipient (local part only)
diff --git a/tests/data/test959 b/tests/data/test959
index ccaec904bf..9708cdc6b6 100644
--- a/tests/data/test959
+++ b/tests/data/test959
@@ -26,7 +26,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based sender (host part only)
diff --git a/tests/data/test960 b/tests/data/test960
index 966f1065e6..4b6a7b0713 100644
--- a/tests/data/test960
+++ b/tests/data/test960
@@ -23,7 +23,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP without SMTPUTF8 support - UTF-8 based recipient (host part only)
diff --git a/tests/data/test961 b/tests/data/test961
index 1be4b5b1ae..22a00d77d8 100644
--- a/tests/data/test961
+++ b/tests/data/test961
@@ -24,7 +24,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP external VRFY without SMTPUTF8 - UTF-8 recipient (host part only)
diff --git a/tests/data/test962 b/tests/data/test962
index 9d674d9410..808c7cbb20 100644
--- a/tests/data/test962
+++ b/tests/data/test962
@@ -24,7 +24,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.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 3845250b96..a8e7807a4a 100644
--- a/tests/data/test963
+++ b/tests/data/test963
@@ -24,7 +24,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP without SMTPUTF8 support (IDN) - UTF-8 recipient (host part only)
diff --git a/tests/data/test964 b/tests/data/test964
index b866def6c6..2492361a1c 100644
--- a/tests/data/test964
+++ b/tests/data/test964
@@ -25,7 +25,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP external VRFY without SMTPUTF8 (IDN) - UTF-8 recipient (host part)
diff --git a/tests/data/test965 b/tests/data/test965
index 4fe35cdb10..78ac103215 100644
--- a/tests/data/test965
+++ b/tests/data/test965
@@ -27,7 +27,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP with SMTPUTF8 support - UTF-8 based sender
diff --git a/tests/data/test966 b/tests/data/test966
index c08fff4086..a74fe52b46 100644
--- a/tests/data/test966
+++ b/tests/data/test966
@@ -27,7 +27,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP with SMTPUTF8 support - UTF-8 based recipient
diff --git a/tests/data/test967 b/tests/data/test967
index 92e109879b..6525edebc8 100644
--- a/tests/data/test967
+++ b/tests/data/test967
@@ -31,7 +31,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP external VRFY with SMTPUTF8 support
diff --git a/tests/data/test968 b/tests/data/test968
index 76c8bece1b..d9673564a8 100644
--- a/tests/data/test968
+++ b/tests/data/test968
@@ -28,7 +28,7 @@ codeset-utf8
 </features>
 <setenv>
 PLACEHOLDER1
-PLACEHOLDER2=1
+LC_CTYPE=en_US.UTF-8
 </setenv>
 <name>
 SMTP VRFY with SMTPUTF8 support