diff --git a/base/strings/string.jl b/base/strings/string.jl
index 30a0fb6d830650..727e9b5168216d 100644
--- a/base/strings/string.jl
+++ b/base/strings/string.jl
@@ -96,9 +96,9 @@ function ==(a::String, b::String)
     al == sizeof(b) && 0 == ccall(:memcmp, Int32, (Ptr{UInt8}, Ptr{UInt8}, UInt), a, b, al)
 end
 
-## thisind, prevind, nextind ##
+## thisind, nextind ##
 
-function thisind(s::String, i::Int)
+function thisind(s::Union{String, SubString{String}}, i::Int)
     n = ncodeunits(s)
     i == n + 1 && return i
     @boundscheck between(i, 0, n) || throw(BoundsError(s, i))
@@ -115,7 +115,7 @@ function thisind(s::String, i::Int)
     return i
 end
 
-function nextind(s::String, i::Int)
+function nextind(s::Union{String, SubString{String}}, i::Int)
     i == 0 && return 1
     n = ncodeunits(s)
     @boundscheck between(i, 1, n) || throw(BoundsError(s, i))
diff --git a/base/strings/substring.jl b/base/strings/substring.jl
index f4cf3c93115378..ce0e6f578ed2bb 100644
--- a/base/strings/substring.jl
+++ b/base/strings/substring.jl
@@ -78,27 +78,6 @@ function isvalid(s::SubString, i::Integer)
     @inbounds return ib && isvalid(s.string, s.offset + i)
 end
 
-function thisind(s::SubString, i::Int)
-    @boundscheck 0 ≤ i ≤ ncodeunits(s)+1 || throw(BoundsError(s, i))
-    @inbounds return thisind(s.string, s.offset + i) - s.offset
-end
-function nextind(s::SubString, i::Int, n::Int)
-    @boundscheck 0 ≤ i < ncodeunits(s)+1 || throw(BoundsError(s, i))
-    @inbounds return nextind(s.string, s.offset + i, n) - s.offset
-end
-function nextind(s::SubString, i::Int)
-    @boundscheck 0 ≤ i < ncodeunits(s)+1 || throw(BoundsError(s, i))
-    @inbounds return nextind(s.string, s.offset + i) - s.offset
-end
-function prevind(s::SubString, i::Int, n::Int)
-    @boundscheck 0 < i ≤ ncodeunits(s)+1 || throw(BoundsError(s, i))
-    @inbounds return prevind(s.string, s.offset + i, n) - s.offset
-end
-function prevind(s::SubString, i::Int)
-    @boundscheck 0 < i ≤ ncodeunits(s)+1 || throw(BoundsError(s, i))
-    @inbounds return prevind(s.string, s.offset + i) - s.offset
-end
-
 function cmp(a::SubString{String}, b::SubString{String})
     na = sizeof(a)
     nb = sizeof(b)
diff --git a/test/strings/types.jl b/test/strings/types.jl
index 0eefac0549c3c0..ea4127d8b4c649 100644
--- a/test/strings/types.jl
+++ b/test/strings/types.jl
@@ -188,6 +188,25 @@ let s = "lorem ipsum", sdict = Dict(
     end
 end
 
+# proper nextind/prevind/thisind for SubString{String}
+let s = "∀∃∀", ss = SubString(s, 4, 4), s2 = s[4:4]
+    for i in 0:4
+        @test thisind(ss, i) == thisind(s2, i)
+    end
+    for i in 0:3
+        @test nextind(ss, i) == nextind(s2, i)
+        for j in 0:10
+            @test nextind(ss, i, j) == nextind(s2, i, j)
+        end
+    end
+    for i in 1:4
+        @test prevind(ss, i) == prevind(s2, i)
+        for j in 0:10
+            @test prevind(ss, i, j) == prevind(s2, i, j)
+        end
+    end
+end
+
 # for isvalid(SubString{String})
 let s = "Σx + βz - 2"
     for i in -1:ncodeunits(s)+2