diff --git a/src/definitions.jl b/src/definitions.jl
index b481a3a..016e622 100644
--- a/src/definitions.jl
+++ b/src/definitions.jl
@@ -272,11 +272,12 @@ summary(p::ScaledPlan) = string(p.scale, " * ", summary(p.p))
 
 # Normalization for ifft, given unscaled bfft, is 1/prod(dimensions)
 # ensure that region is a subset of eachindex(sz).
-_checkindex(sz, region::AbstractVector) = checkindex(Bool, sz, region)
+_checkindex(szinds, region::AbstractVector) = checkindex(Bool, szinds, region)
 # this method handles the case where region is not an array, e.g. it is a Tuple
-_checkindex(sz, region) = all(r -> checkindex(Bool, eachindex(sz), r), region)
-function normalization(::Type{T}, sz, region) where T
-    @boundscheck !isempty(region) && _checkindex(eachindex(sz), region)
+_checkindex(szinds, region) = all(r -> checkindex(Bool, szinds, r), region)
+@inline function normalization(::Type{T}, sz, region) where T
+    @boundscheck (!isempty(region) && _checkindex(eachindex(sz), region)) ||
+        throw(BoundsError(sz, region))
     one(T) / mapreduce(r -> Int(@inbounds sz[r])::Int, *, region; init=oneunit(eltype(sz)))::Int
 end
 normalization(X, region) = normalization(real(eltype(X)), size(X), region)
diff --git a/test/runtests.jl b/test/runtests.jl
index 4d402c5..ced5927 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -211,6 +211,10 @@ end
     # p::TestPlan)
     f9(p::Plan{T}, sz) where {T} = AbstractFFTs.normalization(real(T), sz, fftdims(p))
     @test @inferred(f9(plan_fft(zeros(10), 1), 10)) == 1/10
+
+    @test_throws BoundsError AbstractFFTs.normalization(Float64, (2,), 1:3)
+    @test_throws BoundsError AbstractFFTs.normalization(Float64, (2,), Int[])
+    @test_throws BoundsError AbstractFFTs.normalization(Float64, (2,), (1,3,))
 end
 
 @testset "ChainRules" begin