diff --git a/tests/ui/diagnostic-width/non-1-width-unicode-multiline-label.rs b/tests/ui/diagnostic-width/non-1-width-unicode-multiline-label.rs
index 0940b987fea1..7fb95a4ac1e2 100644
--- a/tests/ui/diagnostic-width/non-1-width-unicode-multiline-label.rs
+++ b/tests/ui/diagnostic-width/non-1-width-unicode-multiline-label.rs
@@ -1,5 +1,5 @@
 //@ revisions: ascii unicode
-
+//@ compile-flags: --diagnostic-width=145
 //@[unicode] compile-flags: -Zunstable-options --error-format=human-unicode
 // ignore-tidy-linelength
 
diff --git a/tests/ui/diagnostic-width/non-whitespace-trimming-2.rs b/tests/ui/diagnostic-width/non-whitespace-trimming-2.rs
index cdbef418f888..6e80649fee86 100644
--- a/tests/ui/diagnostic-width/non-whitespace-trimming-2.rs
+++ b/tests/ui/diagnostic-width/non-whitespace-trimming-2.rs
@@ -1,5 +1,5 @@
 //@ revisions: ascii unicode
-
+//@ compile-flags: --diagnostic-width=145
 //@[unicode] compile-flags: -Zunstable-options --error-format=human-unicode
 // ignore-tidy-linelength
 
diff --git a/tests/ui/diagnostic-width/non-whitespace-trimming-unicode.rs b/tests/ui/diagnostic-width/non-whitespace-trimming-unicode.rs
index f5d1926e1eb6..258eb090aae3 100644
--- a/tests/ui/diagnostic-width/non-whitespace-trimming-unicode.rs
+++ b/tests/ui/diagnostic-width/non-whitespace-trimming-unicode.rs
@@ -1,4 +1,4 @@
-
+//@ compile-flags: --diagnostic-width=145
 // ignore-tidy-linelength
 
 fn main() {
diff --git a/tests/ui/diagnostic-width/non-whitespace-trimming.rs b/tests/ui/diagnostic-width/non-whitespace-trimming.rs
index 67066157a60a..cb9450f0de0b 100644
--- a/tests/ui/diagnostic-width/non-whitespace-trimming.rs
+++ b/tests/ui/diagnostic-width/non-whitespace-trimming.rs
@@ -1,4 +1,4 @@
-
+//@ compile-flags: --diagnostic-width=145
 // ignore-tidy-linelength
 
 fn main() {
diff --git a/tests/ui/diagnostic-width/tabs-trimming.rs b/tests/ui/diagnostic-width/tabs-trimming.rs
index 96babde33e9a..5cf6bc89a167 100644
--- a/tests/ui/diagnostic-width/tabs-trimming.rs
+++ b/tests/ui/diagnostic-width/tabs-trimming.rs
@@ -1,5 +1,5 @@
 // Test for #78438: ensure underline alignment with many tabs on the left, long line on the right
-
+//@ compile-flags: --diagnostic-width=145
 // ignore-tidy-linelength
 // ignore-tidy-tab