diff --git a/base/linalg/bidiag.jl b/base/linalg/bidiag.jl
index 16c9729d7d9c2..41e0acc8091c4 100644
--- a/base/linalg/bidiag.jl
+++ b/base/linalg/bidiag.jl
@@ -263,8 +263,8 @@ end
 transpose(M::Bidiagonal) = Bidiagonal(M.dv, M.ev, !M.isupper)
 ctranspose(M::Bidiagonal) = Bidiagonal(conj(M.dv), conj(M.ev), !M.isupper)
 
-istriu(M::Bidiagonal) = M.isupper || all(M.ev .== 0)
-istril(M::Bidiagonal) = !M.isupper || all(M.ev .== 0)
+istriu(M::Bidiagonal) = M.isupper || all(M.ev .== zero(eltype(M)))
+istril(M::Bidiagonal) = !M.isupper || all(M.ev .== zero(eltype(M)))
 
 function tril!(M::Bidiagonal, k::Integer=0)
     n = length(M.dv)
diff --git a/base/linalg/generic.jl b/base/linalg/generic.jl
index 7fad30d4d5499..b5e488556d4fc 100644
--- a/base/linalg/generic.jl
+++ b/base/linalg/generic.jl
@@ -870,8 +870,9 @@ true
 """
 function istriu(A::AbstractMatrix)
     m, n = size(A)
+    z = zero(eltype(A))
     for j = 1:min(n,m-1), i = j+1:m
-        if A[i,j] != 0
+        if A[i,j] != z
             return false
         end
     end
@@ -905,8 +906,9 @@ true
 """
 function istril(A::AbstractMatrix)
     m, n = size(A)
+    z = zero(eltype(A))
     for j = 2:n, i = 1:min(j-1,m)
-        if A[i,j] != 0
+        if A[i,j] != z
             return false
         end
     end
diff --git a/base/linalg/tridiag.jl b/base/linalg/tridiag.jl
index b1fe565ebb088..33df93e733693 100644
--- a/base/linalg/tridiag.jl
+++ b/base/linalg/tridiag.jl
@@ -206,8 +206,8 @@ eigvecs{T<:BlasFloat,Eigenvalue<:Real}(A::SymTridiagonal{T}, eigvals::Vector{Eig
 
 #tril and triu
 
-istriu(M::SymTridiagonal) = all(M.ev .== 0)
-istril(M::SymTridiagonal) = all(M.ev .== 0)
+istriu(M::SymTridiagonal) = all(M.ev .== zero(eltype(M)))
+istril(M::SymTridiagonal) = all(M.ev .== zero(eltype(M)))
 
 function tril!(M::SymTridiagonal, k::Integer=0)
     n = length(M.dv)
@@ -526,8 +526,8 @@ end
 
 #tril and triu
 
-istriu(M::Tridiagonal) = all(M.dl .== 0)
-istril(M::Tridiagonal) = all(M.du .== 0)
+istriu(M::Tridiagonal) = all(M.dl .== zero(eltype(M)))
+istril(M::Tridiagonal) = all(M.du .== zero(eltype(M)))
 
 function tril!(M::Tridiagonal, k::Integer=0)
     n = length(M.d)