diff --git a/base/socket.jl b/base/socket.jl
index bea4c64454387..31667d2a21a89 100644
--- a/base/socket.jl
+++ b/base/socket.jl
@@ -148,6 +148,11 @@ end
 
 # Parsing
 
+const ipv4_leading_zero_error = """
+Leading zeros in IPv4 addresses are disallowed due to ambiguity.
+If the address is in octal or hexadecimal, convert it to decimal, otherwise remove the leading zero.
+"""
+
 function parse(::Type{IPv4}, str::AbstractString)
     fields = split(str,'.')
     i = 1
@@ -156,18 +161,8 @@ function parse(::Type{IPv4}, str::AbstractString)
         if isempty(f)
             throw(ArgumentError("empty field in IPv4 address"))
         end
-        if f[1] == '0'
-            if length(f) >= 2 && f[2] == 'x'
-                if length(f) > 8 # 2+(3*2) - prevent parseint from overflowing on 32bit
-                    throw(ArgumentError("IPv4 field too large"))
-                end
-                r = parse(Int,f[3:end],16)
-            else
-                if length(f) > 9 # 1+8 - prevent parseint from overflowing on 32bit
-                    throw(ArgumentError("IPv4 field too large"))
-                end
-                r = parse(Int,f,8)
-            end
+        if length(f) > 1 && f[1] == '0'
+            throw(ArgumentError(ipv4_leading_zero_error))
         else
             r = parse(Int,f,10)
         end
diff --git a/test/socket.jl b/test/socket.jl
index 03eaabd6195c8..9d5421824f04b 100644
--- a/test/socket.jl
+++ b/test/socket.jl
@@ -2,11 +2,13 @@
 
 @test ip"127.0.0.1" == IPv4(127,0,0,1)
 @test ip"192.0" == IPv4(192,0,0,0)
-@test ip"192.0xFFF" == IPv4(192,0,15,255)
-@test ip"192.0xFFFF" == IPv4(192,0,255,255)
-@test ip"192.0xFFFFF" == IPv4(192,15,255,255)
-@test ip"192.0xFFFFFF" == IPv4(192,255,255,255)
-@test ip"022.0.0.1" == IPv4(18,0,0,1)
+
+# These used to work, but are now disallowed. Check that they error
+@test_throws ArgumentError parse(IPv4, "192.0xFFF") # IPv4(192,0,15,255)
+@test_throws ArgumentError parse(IPv4, "192.0xFFFF") # IPv4(192,0,255,255)
+@test_throws ArgumentError parse(IPv4, "192.0xFFFFF") # IPv4(192,15,255,255)
+@test_throws ArgumentError parse(IPv4, "192.0xFFFFFF") # IPv4(192,255,255,255)
+@test_throws ArgumentError parse(IPv4, "022.0.0.1") # IPv4(18,0,0,1)
 
 @test UInt(IPv4(0x01020304)) == 0x01020304
 @test Int(IPv4("1.2.3.4")) == Int(0x01020304) == Int32(0x01020304)