diff --git a/base/string.jl b/base/string.jl
index a10857dca76f18..99556e1d489f50 100644
--- a/base/string.jl
+++ b/base/string.jl
@@ -1551,7 +1551,8 @@ function tryparse_internal{T<:Integer}(::Type{T}, s::AbstractString, base::Int,
     end
 
     base = convert(T,base)
-    m::T = div(typemax(T)-base+1,base)
+    #m::T = div(typemax(T)-base+1,base)
+    m::T = ((T===UInt128 || T===Int128) && (Base.WORD_SIZE < 64)) ? typemax(T) : div(typemax(T)-base+1,base)
     n::T = 0
     while n <= m
         d::T = '0' <= c <= '9' ? c-'0'    :
@@ -1581,13 +1582,25 @@ function tryparse_internal{T<:Integer}(::Type{T}, s::AbstractString, base::Int,
         end
         (T <: Signed) && (d *= sgn)
 
-        safe_n = safe_mul(n, base)
-        safe_n.isnull || (safe_n = safe_add(safe_n.value, d))
-        if safe_n.isnull
-            raise && throw(OverflowError())
-            return _n
+        if (T===UInt128 || T===Int128) && (Base.WORD_SIZE < 64)
+            if raise
+                n = checked_add(checked_mul(n,base),d)
+            else
+                try
+                    n = checked_add(checked_mul(n,base),d)
+                catch
+                    return _n
+                end
+            end
+        else
+            safe_n = safe_mul(n, base)
+            safe_n.isnull || (safe_n = safe_add(safe_n.value, d))
+            if safe_n.isnull
+                raise && throw(OverflowError())
+                return _n
+            end
+            n = safe_n.value
         end
-        n = safe_n.value
         done(s,i) && return Nullable{T}(n)
         c, i = next(s,i)
     end