diff --git a/j/env.j b/j/env.j
index 2262d11ebdffb..228b5211f43cb 100644
--- a/j/env.j
+++ b/j/env.j
@@ -53,11 +53,10 @@ has(::EnvHash, k::String) = hasenv(k)
 del(::EnvHash, k::String) = unsetenv(k)
 assign(::EnvHash, v::String, k::String) = (setenv(k,v); v)
 
-start(::EnvHash) = int32(0)
+start(::EnvHash) = 0
 done(::EnvHash, i) = (ccall(:jl_environ, Any, (Int32,), int32(i)) == nothing)
 function next(::EnvHash, i)
-    i = int32(i)
-    env = ccall(:jl_environ, Any, (Int32,), i)
+    env = ccall(:jl_environ, Any, (Int32,), int32(i))
     if env == nothing
         error("environ: index out of range")
     end
@@ -66,7 +65,7 @@ function next(::EnvHash, i)
     if m == nothing
         error("malformed environment entry: $env")
     end
-    (m.captures, i+one(i))
+    (m.captures, i+1)
 end
 
 function show(::EnvHash)
diff --git a/j/int.j b/j/int.j
index 24ec123567503..7bc3346a10eb6 100644
--- a/j/int.j
+++ b/j/int.j
@@ -182,7 +182,7 @@ promote_rule(::Type{Uint64}, ::Type{Int64}) = Uint64 # LOSSY
 -(x::Uint8 ) = boxsi16(neg_int(zext16(unbox8 (x))))
 -(x::Uint16) = boxsi32(neg_int(zext32(unbox16(x))))
 -(x::Uint32) = boxsi64(neg_int(zext64(unbox32(x))))
--(x::Uint64) = boxsi64(neg_int(unbox64(x))) # LOSSY
+-(x::Uint64) = boxui64(neg_int(unbox64(x))) # LOSSY
 
 +(x::Int8 , y::Int8 ) = boxsi8 (add_int(unbox8 (x), unbox8 (y)))
 +(x::Int16, y::Int16) = boxsi16(add_int(unbox16(x), unbox16(y)))
diff --git a/j/sparse.j b/j/sparse.j
index c653ab422a3bc..38891ef201d54 100644
--- a/j/sparse.j
+++ b/j/sparse.j
@@ -228,7 +228,7 @@ end
 function istril{T}(A::SparseMatrixCSC{T})
     for col = 1:A.n
         for i = A.colptr[col]:(A.colptr[col]-1)
-            if A.rowval[i] < col && A.nzval[i] != zero(T); return false; end
+            if A.rowval[i] < col && A.nzval[i] != 0; return false; end
         end
     end
     return true
@@ -237,7 +237,7 @@ end
 function istriu{T}(A::SparseMatrixCSC{T})
     for col = 1:A.n
         for i = A.colptr[col]:(A.colptr[col]-1)
-            if A.rowval[i] > col && A.nzval[i] != zero(T); return false; end
+            if A.rowval[i] > col && A.nzval[i] != 0; return false; end
         end
     end
     return true
@@ -512,7 +512,7 @@ function assign{T,T_int}(A::SparseMatrixCSC{T,T_int}, v, i0::Integer, i1::Intege
     i1 = convert(T_int, i1)
     if i0 < 1 || i0 > A.m || i1 < 1 || i1 > A.n; error("assign: index out of bounds"); end
     v = convert(T, v)
-    if v == zero(T) #either do nothing or delete entry if it exists
+    if v == 0 #either do nothing or delete entry if it exists
         first = A.colptr[i1]
         last = A.colptr[i1+1]-1
         loc = -1
@@ -884,7 +884,7 @@ assign{T,N}(S::SparseAccumulator{T}, v::AbstractArray{T,N}, i::Integer) =
     invoke(assign, (SparseAccumulator{T}, Any, Integer), S, v, i)
 
 function assign{T}(S::SparseAccumulator{T}, v, i::Integer)
-    if v == zero(T)
+    if v == 0
         if S.flags[i]
             S.vals[i] = v
             S.flags[i] = false
diff --git a/j/string.j b/j/string.j
index adac4113bb8f1..860a4ff168b1a 100644
--- a/j/string.j
+++ b/j/string.j
@@ -831,9 +831,16 @@ function ndigits(n::Integer, b::Integer)
     return nd
 end
 
-function int2str(n::Integer, b::Integer)
+int2str(n::Integer, b::Integer) = int2str(int64(n), b)
+
+function int2str(n::Union(Int64,Uint64), b::Integer)
     if b < 2 || b > 40; error("int2str: invalid base ", b); end
-    neg = n<zero(n) ? 1 : 0
+    if n == typemin(Int64)
+        # this is really cheap, but the algorithm fails in this case
+        # since abs(n) is still negative.
+        return "-9223372036854775808"
+    end
+    neg = n<0 ? 1 : 0
     n = abs(n)
     b = convert(typeof(n), b)
     ndig = ndigits(n, b)
diff --git a/j/utf8.j b/j/utf8.j
index 6778334b0d897..80e54390568a5 100644
--- a/j/utf8.j
+++ b/j/utf8.j
@@ -41,10 +41,10 @@ function next(s::UTF8String, i::Int)
     for j = 1:trailing
         c += s.data[i]
         c <<= 6
-        i += one(i)
+        i += 1
     end
     c += s.data[i]
-    i += one(i)
+    i += 1
     c -= _jl_utf8_offset[trailing+1]
     char(c), i
 end
diff --git a/test/core.j b/test/core.j
index 6f56c14a97550..7c530bf45e2b0 100644
--- a/test/core.j
+++ b/test/core.j
@@ -614,6 +614,10 @@ end
 @assert hex(0xffffffffffff+1)=="1000000000000"
 @assert hex(typemax(Uint64))=="ffffffffffffffff"
 
+@assert int2str(typemin(Int64), 10) == "-9223372036854775808"
+@assert int2str(typemin(Int16), 10) == "-32768"
+@assert int2str(typemin(Int8 ), 10) == "-128"
+
 # conversions
 function fooo()
     local x::Int8