diff --git a/base/broadcast.jl b/base/broadcast.jl
index 90453ccf19aa3..91dbff6dc6ea3 100644
--- a/base/broadcast.jl
+++ b/base/broadcast.jl
@@ -517,8 +517,8 @@ function _bcs(shape::Tuple, newshape::Tuple)
     return (_bcs1(shape[1], newshape[1]), _bcs(tail(shape), tail(newshape))...)
 end
 # _bcs1 handles the logic for a single dimension
-_bcs1(a::Integer, b::Integer) = a == 1 ? b : (b == 1 ? a : (a == b ? a : throw(DimensionMismatch("arrays could not be broadcast to a common size; got a dimension with lengths $a and $b"))))
-_bcs1(a::Integer, b) = a == 1 ? b : (first(b) == 1 && last(b) == a ? b : throw(DimensionMismatch("arrays could not be broadcast to a common size; got a dimension with lengths $a and $(length(b))")))
+_bcs1(a::Integer, b::Integer) = a == 1 ? b : (b == 1 ? a : (a == b ? a : throw(DimensionMismatch(LazyString("arrays could not be broadcast to a common size; got a dimension with lengths ", a, " and ", b)))))
+_bcs1(a::Integer, b) = a == 1 ? b : (first(b) == 1 && last(b) == a ? b : throw(DimensionMismatch(LazyString("arrays could not be broadcast to a common size; got a dimension with lengths ", a, " and ", length(b)))))
 _bcs1(a, b::Integer) = _bcs1(b, a)
 _bcs1(a, b) = _bcsm(b, a) ? axistype(b, a) : _bcsm(a, b) ? axistype(a, b) : throw(DimensionMismatch(LazyString("arrays could not be broadcast to a common size: a has axes ", a, " and b has axes ", b)))
 # _bcsm tests whether the second index is consistent with the first
@@ -1057,7 +1057,7 @@ end
 
 
 @noinline throwdm(axdest, axsrc) =
-    throw(DimensionMismatch("destination axes $axdest are not compatible with source axes $axsrc"))
+    throw(DimensionMismatch(LazyString("destination axes ", axdest, " are not compatible with source axes ", axsrc)))
 
 function restart_copyto_nonleaf!(newdest, dest, bc, val, I, iter, state, count)
     # Function barrier that makes the copying to newdest type stable