diff --git a/Project.toml b/Project.toml
index 6bdeb6c..8bf8163 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "NFFT"
 uuid = "efe261a4-0d2b-5849-be55-fc731d526b0d"
 authors = ["Tobias Knopp <tobias@knoppweb.de>"]
-version = "0.12.0"
+version = "0.12.1"
 
 [deps]
 AbstractNFFTs = "7f219486-4aa7-41d6-80a7-e08ef20ceed7"
diff --git a/src/implementation.jl b/src/implementation.jl
index 7a7a47d..691e990 100644
--- a/src/implementation.jl
+++ b/src/implementation.jl
@@ -3,7 +3,7 @@
 Base.@kwdef mutable struct NFFTParams{T}
   m::Int = 4
   σ::T = 2.0
-  reltol::T = 1e-9
+  reltol::T = 1e-7
   window::Symbol = :kaiser_bessel
   LUTSize::Int64 = 0
   precompute::PrecomputeFlags = POLYNOMIAL
diff --git a/src/multidimensional.jl b/src/multidimensional.jl
index 241ad91..ab241a9 100644
--- a/src/multidimensional.jl
+++ b/src/multidimensional.jl
@@ -383,7 +383,8 @@ end
 
 @noinline function fillBlock!(p::NFFTPlan{T,D,1}, fHat, block, nodesInBlock, off, L::Val{Z}, scale, 
                               idxInBlock, winTensor, winPoly) where {T,D,Z}
-  if (D >= 3 && Z >= 10) || (D == 2 && Z >= 16) # magic
+  if (Threads.nthreads() == 1 || !NFFT._use_threads[]) &&
+      (D >= 3 && Z >= 10) || (D == 2 && Z >= 16) # magic 
     for (kLocal,k) in enumerate(nodesInBlock)
       fillOneNodeReal!(p, fHat, block, off, L, scale, k, kLocal, idxInBlock, winTensor, winPoly)
     end