diff --git a/src/test/run-pass/optimization-fuel-0.rs b/src/test/run-pass/optimization-fuel-0.rs
index 3832c040108f..a12dad4489df 100644
--- a/src/test/run-pass/optimization-fuel-0.rs
+++ b/src/test/run-pass/optimization-fuel-0.rs
@@ -12,7 +12,8 @@
 
 use std::mem::size_of;
 
-// compile-flags: -Z fuel=foo=0
+// (#55495: The --error-format is to sidestep an issue in our test harness)
+// compile-flags: --error-format human -Z fuel=foo=0
 
 struct S1(u8, u16, u8);
 struct S2(u8, u16, u8);
diff --git a/src/test/run-pass/optimization-fuel-0.stdout b/src/test/run-pass/optimization-fuel-0.stderr
similarity index 100%
rename from src/test/run-pass/optimization-fuel-0.stdout
rename to src/test/run-pass/optimization-fuel-0.stderr
diff --git a/src/test/run-pass/optimization-fuel-1.rs b/src/test/run-pass/optimization-fuel-1.rs
index e3529ebfb0d8..1e76aaa48b76 100644
--- a/src/test/run-pass/optimization-fuel-1.rs
+++ b/src/test/run-pass/optimization-fuel-1.rs
@@ -12,7 +12,8 @@
 
 use std::mem::size_of;
 
-// compile-flags: -Z fuel=foo=1
+// (#55495: The --error-format is to sidestep an issue in our test harness)
+// compile-flags: --error-format human -Z fuel=foo=1
 
 struct S1(u8, u16, u8);
 struct S2(u8, u16, u8);
diff --git a/src/test/run-pass/optimization-fuel-1.stdout b/src/test/run-pass/optimization-fuel-1.stderr
similarity index 100%
rename from src/test/run-pass/optimization-fuel-1.stdout
rename to src/test/run-pass/optimization-fuel-1.stderr
diff --git a/src/test/ui/print-fuel/print-fuel.rs b/src/test/ui/print-fuel/print-fuel.rs
index 96b025128ee9..31123410481c 100644
--- a/src/test/ui/print-fuel/print-fuel.rs
+++ b/src/test/ui/print-fuel/print-fuel.rs
@@ -11,7 +11,8 @@
 #![crate_name="foo"]
 #![allow(dead_code)]
 
-// compile-flags: -Z print-fuel=foo
+// (#55495: The --error-format is to sidestep an issue in our test harness)
+// compile-flags: --error-format human -Z print-fuel=foo
 // compile-pass
 
 struct S1(u8, u16, u8);
diff --git a/src/test/ui/print-fuel/print-fuel.stdout b/src/test/ui/print-fuel/print-fuel.stderr
similarity index 100%
rename from src/test/ui/print-fuel/print-fuel.stdout
rename to src/test/ui/print-fuel/print-fuel.stderr