diff --git a/src/doc/trpl/casting-between-types.md b/src/doc/trpl/casting-between-types.md
index dbacd405065..148c55e4b97 100644
--- a/src/doc/trpl/casting-between-types.md
+++ b/src/doc/trpl/casting-between-types.md
@@ -82,7 +82,7 @@ unsafe {
 with:
 
 ```text
-error: transmute called on types with different sizes: [u8; 4] (32 bits) to u64
+error: transmute called with differently sized types: [u8; 4] (32 bits) to u64
 (64 bits)
 ```
 
diff --git a/src/librustc_trans/trans/intrinsic.rs b/src/librustc_trans/trans/intrinsic.rs
index 0573d6301c5..5e781bdf330 100644
--- a/src/librustc_trans/trans/intrinsic.rs
+++ b/src/librustc_trans/trans/intrinsic.rs
@@ -135,7 +135,7 @@ pub fn check_intrinsics(ccx: &CrateContext) {
 
             if transmute_restriction.original_from != transmute_restriction.substituted_from {
                 span_transmute_size_error(ccx.sess(), transmute_restriction.span,
-                    &format!("transmute called on types with potentially different sizes: \
+                    &format!("transmute called with differently sized types: \
                               {} (could be {} bit{}) to {} (could be {} bit{})",
                              transmute_restriction.original_from,
                              from_type_size as usize,
@@ -145,7 +145,7 @@ pub fn check_intrinsics(ccx: &CrateContext) {
                              if to_type_size == 1 {""} else {"s"}));
             } else {
                 span_transmute_size_error(ccx.sess(), transmute_restriction.span,
-                    &format!("transmute called on types with different sizes: \
+                    &format!("transmute called with differently sized types: \
                               {} ({} bit{}) to {} ({} bit{})",
                              transmute_restriction.original_from,
                              from_type_size as usize,
diff --git a/src/test/compile-fail/packed-struct-generic-transmute.rs b/src/test/compile-fail/packed-struct-generic-transmute.rs
index 82425d2c227..2c345e6c8ab 100644
--- a/src/test/compile-fail/packed-struct-generic-transmute.rs
+++ b/src/test/compile-fail/packed-struct-generic-transmute.rs
@@ -13,7 +13,7 @@
 // the error points to the start of the file, not the line with the
 // transmute
 
-// error-pattern: transmute called on types with different size
+// error-pattern: transmute called with differently sized types
 
 use std::mem;
 
diff --git a/src/test/compile-fail/packed-struct-transmute.rs b/src/test/compile-fail/packed-struct-transmute.rs
index 1b164709ac7..94f2522f3eb 100644
--- a/src/test/compile-fail/packed-struct-transmute.rs
+++ b/src/test/compile-fail/packed-struct-transmute.rs
@@ -13,7 +13,7 @@
 // the error points to the start of the file, not the line with the
 // transmute
 
-// error-pattern: transmute called on types with different size
+// error-pattern: transmute called with differently sized types
 
 use std::mem;
 
diff --git a/src/test/compile-fail/transmute-different-sizes.rs b/src/test/compile-fail/transmute-different-sizes.rs
index 918589b8fd3..df87a7bbdc9 100644
--- a/src/test/compile-fail/transmute-different-sizes.rs
+++ b/src/test/compile-fail/transmute-different-sizes.rs
@@ -16,12 +16,12 @@ use std::mem::transmute;
 
 unsafe fn f() {
     let _: i8 = transmute(16i16);
-    //~^ ERROR transmute called on types with different sizes
+    //~^ ERROR transmute called with differently sized types
 }
 
 unsafe fn g<T>(x: &T) {
     let _: i8 = transmute(x);
-    //~^ ERROR transmute called on types with potentially different sizes
+    //~^ ERROR transmute called with differently sized types
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/transmute-fat-pointers.rs b/src/test/compile-fail/transmute-fat-pointers.rs
index 31456853e1c..f7324247f3b 100644
--- a/src/test/compile-fail/transmute-fat-pointers.rs
+++ b/src/test/compile-fail/transmute-fat-pointers.rs
@@ -15,11 +15,11 @@
 use std::mem::transmute;
 
 fn a<T, U: ?Sized>(x: &[T]) -> &U {
-    unsafe { transmute(x) } //~ ERROR transmute called on types with potentially different sizes
+    unsafe { transmute(x) } //~ ERROR transmute called with differently sized types
 }
 
 fn b<T: ?Sized, U: ?Sized>(x: &T) -> &U {
-    unsafe { transmute(x) } //~ ERROR transmute called on types with potentially different sizes
+    unsafe { transmute(x) } //~ ERROR transmute called with differently sized types
 }
 
 fn c<T, U>(x: &T) -> &U {
@@ -31,11 +31,11 @@ fn d<T, U>(x: &[T]) -> &[U] {
 }
 
 fn e<T: ?Sized, U>(x: &T) -> &U {
-    unsafe { transmute(x) } //~ ERROR transmute called on types with potentially different sizes
+    unsafe { transmute(x) } //~ ERROR transmute called with differently sized types
 }
 
 fn f<T, U: ?Sized>(x: &T) -> &U {
-    unsafe { transmute(x) } //~ ERROR transmute called on types with potentially different sizes
+    unsafe { transmute(x) } //~ ERROR transmute called with differently sized types
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/transmute-impl.rs b/src/test/compile-fail/transmute-impl.rs
index a77a37a77e1..55cebbd6cfc 100644
--- a/src/test/compile-fail/transmute-impl.rs
+++ b/src/test/compile-fail/transmute-impl.rs
@@ -26,7 +26,7 @@ impl<T: ?Sized> Foo<T> {
 
     fn n(x: &T) -> &isize {
         // Not OK here, because T : Sized is not in scope.
-        unsafe { transmute(x) } //~ ERROR transmute called on types with potentially different sizes
+        unsafe { transmute(x) } //~ ERROR transmute called with differently sized types
     }
 }