diff --git a/.gitignore b/.gitignore
index 8c960ec..3f02ca7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 *.jl.cov
 *.jl.*.cov
 *.jl.mem
+Manifest.toml
diff --git a/src/group.jl b/src/group.jl
index 96d0a55..6ad3c82 100644
--- a/src/group.jl
+++ b/src/group.jl
@@ -52,7 +52,8 @@ function group(groups, values)
 
     out = Dictionary{I, Vector{T}}()
     @inbounds for (group, value) in zip(groups, values)
-        push!(get!(Vector{T}, out, group), value)
+        tmp = get!(() -> T[value], out, group)
+        last(tmp) == value || push!(tmp, value)
     end
 
     return out
@@ -295,8 +296,8 @@ function groupfind(container)
 
     out = Dictionary{I, Vector{T}}()
     @inbounds for i in keys(container)
-        tmp = get!(Vector{T}, out, container[i])
-        push!(tmp, i)
+        tmp = get!(() -> T[i], out, container[i])
+        last(tmp) == i || push!(tmp, i)
     end
     return out
 end
@@ -307,8 +308,8 @@ function groupfind(inds::AbstractIndices)
 
     out = Dictionary{I, Vector{T}}()
     for i in inds
-        tmp = get!(Vector{T}, out, i)
-        push!(tmp, i)
+        tmp = get!(() -> T[i], out, container[i])
+        last(tmp) == i || push!(tmp, i)
     end
     return out
 end
diff --git a/test/group.jl b/test/group.jl
index 0881a73..a808a8d 100644
--- a/test/group.jl
+++ b/test/group.jl
@@ -5,6 +5,8 @@
     @test group(iseven, x -> x*2, 1:10)::Dictionary == dictionary([false => [2,6,10,14,18], true => [4,8,12,16,20]])
 
     @test group((x,y) -> iseven(x+y), (x,y) -> x, 1:10, [1,3,4,2,5,6,4,2,3,9])::Dictionary == dictionary([true => [1,4,5,6,8,9], false => [2,3,7,10]])
+
+    @test group(isnothing, [1, 2, 3, nothing, 4, 5, nothing])::Dictionary == dictionary([false => [1, 2, 3, 4, 5], true => [nothing, nothing]])
 end
 
 @testset "grouponly" begin