diff --git a/NDTensors/src/lib/GradedAxes/src/abstractgradedunitrange.jl b/NDTensors/src/lib/GradedAxes/src/abstractgradedunitrange.jl
index 1953230045..8782ddfd61 100644
--- a/NDTensors/src/lib/GradedAxes/src/abstractgradedunitrange.jl
+++ b/NDTensors/src/lib/GradedAxes/src/abstractgradedunitrange.jl
@@ -81,7 +81,7 @@ function tensor_product(
       return fuse(isdual ? dual(l1) : l1, isdual ? dual(l2) : l2)
     end,
   )
-  return gradedrange(a, nondual_sectors_a, isdual)
+  return gradedrange(nondual_sectors_a, a, isdual)
 end
 
 function Base.show(io::IO, mimetype::MIME"text/plain", a::AbstractGradedUnitRange)
diff --git a/NDTensors/src/lib/GradedAxes/src/gradedunitrange.jl b/NDTensors/src/lib/GradedAxes/src/gradedunitrange.jl
index a8bbefc182..256ddf74b9 100644
--- a/NDTensors/src/lib/GradedAxes/src/gradedunitrange.jl
+++ b/NDTensors/src/lib/GradedAxes/src/gradedunitrange.jl
@@ -1,4 +1,5 @@
-using BlockArrays: BlockArrays, Block, BlockRange, BlockedUnitRange, blockedrange
+using BlockArrays:
+  BlockArrays, Block, BlockRange, BlockedUnitRange, blockedrange, blocklength
 
 struct GradedUnitRange{T,S} <: AbstractGradedUnitRange{T,S}
   blockedrange::BlockedUnitRange{T}
@@ -12,6 +13,9 @@ isdual(s::GradedUnitRange) = s.isdual
 dual(s::GradedUnitRange) = GradedUnitRange(blockedrange(s), nondual_sectors(s), !isdual(s))
 
 function gradedrange(nondual_sectors::Vector, blocklengths::Vector{Int}, isdual=false)
+  if length(nondual_sectors) != length(blocklengths)
+    throw(DomainError("Sector and block lengths do not match"))
+  end
   return GradedUnitRange(blockedrange(blocklengths), nondual_sectors, isdual)
 end
 
@@ -19,7 +23,10 @@ function gradedrange(sectors_lengths::Vector{<:Pair{<:Any,Int}}, isdual=false)
   return gradedrange(first.(sectors_lengths), last.(sectors_lengths), isdual)
 end
 
-function gradedrange(a::BlockedUnitRange, nondual_sectors::Vector, isdual=false)
+function gradedrange(nondual_sectors::Vector, a::BlockedUnitRange, isdual=false)
+  if length(nondual_sectors) != blocklength(a)
+    throw(DomainError("Number of sectors and number of blocks do not match"))
+  end
   return GradedUnitRange(a, nondual_sectors, isdual)
 end
 
diff --git a/NDTensors/src/lib/GradedAxes/test/test_basics.jl b/NDTensors/src/lib/GradedAxes/test/test_basics.jl
index 9be177b2b6..0c612c684d 100644
--- a/NDTensors/src/lib/GradedAxes/test/test_basics.jl
+++ b/NDTensors/src/lib/GradedAxes/test/test_basics.jl
@@ -1,5 +1,5 @@
 @eval module $(gensym())
-using BlockArrays: Block, BlockVector, blocklength, blocklengths, findblock
+using BlockArrays: Block, BlockVector, blockedrange, blocklength, blocklengths, findblock
 using NDTensors.GradedAxes:
   GradedAxes,
   blockmergesortperm,
@@ -10,7 +10,7 @@ using NDTensors.GradedAxes:
   sector,
   sectors,
   tensor_product
-using Test: @test, @testset
+using Test: @test, @testset, @test_throws
 
 struct U1
   dim::Int
@@ -23,6 +23,7 @@ GradedAxes.dual(l::U1) = U1(-l.dim)
   a = gradedrange([U1(0), U1(1)], [2, 3])
   @test a isa GradedAxes.GradedUnitRange
   @test a == gradedrange([U1(0) => 2, U1(1) => 3])
+  @test a == gradedrange([U1(0), U1(1)], blockedrange([2, 3]))
   @test length(a) == 5
   @test a == 1:5
   @test a[Block(1)] == 1:2
@@ -44,6 +45,10 @@ GradedAxes.dual(l::U1) = U1(-l.dim)
   @test sector(a, 4) == U1(1)
   @test sector(a, 5) == U1(1)
 
+  # test error for invalid input
+  @test_throws DomainError gradedrange([U1(0), U1(1)], [2, 3, 4])
+  @test_throws DomainError gradedrange([U1(0), U1(1)], blockedrange([2, 3, 4]))
+
   # Naive tensor product, no sorting and merging
   a = gradedrange([U1(0), U1(1)], [2, 3])
   a2 = tensor_product(a, a)