diff --git a/pocketfft_hdronly.h b/pocketfft_hdronly.h
index 1fbb503dfb746d3f99d47d1d2c141a54989be523..2c76ad863ba3bc8521c6f06d6d7f312001d2cbad 100644
--- a/pocketfft_hdronly.h
+++ b/pocketfft_hdronly.h
@@ -474,8 +474,8 @@ struct util // hack to avoid duplicate symbols
     shape_t tmp(ndim,0);
     for (auto ax : axes)
       {
-      if (ax>=ndim) throw runtime_error("bad axis number");
-      if (++tmp[ax]>1) throw runtime_error("axis specified repeatedly");
+      if (ax>=ndim) throw invalid_argument("bad axis number");
+      if (++tmp[ax]>1) throw invalid_argument("axis specified repeatedly");
       }
     }
 
@@ -484,7 +484,7 @@ struct util // hack to avoid duplicate symbols
     size_t axis)
     {
     sanity_check(shape, stride_in, stride_out, inplace);
-    if (axis>=shape.size()) throw runtime_error("bad axis number");
+    if (axis>=shape.size()) throw invalid_argument("bad axis number");
     }
 
 #ifdef POCKETFFT_OPENMP
@@ -1245,7 +1245,7 @@ template<bool fwd, typename T> void pass_all(T c[], T0 fct)
     POCKETFFT_NOINLINE cfftp(size_t length_)
       : length(length_)
       {
-      if (length==0) throw runtime_error("zero length FFT requested");
+      if (length==0) throw runtime_error("zero-length FFT requested");
       if (length==1) return;
       factorize();
       mem.resize(twsize());
@@ -2085,7 +2085,7 @@ template<typename T> void radbg(size_t ido, size_t ip, size_t l1,
     POCKETFFT_NOINLINE rfftp(size_t length_)
       : length(length_)
       {
-      if (length==0) throw runtime_error("zero-sized FFT");
+      if (length==0) throw runtime_error("zero-length FFT requested");
       if (length==1) return;
       factorize();
       mem.resize(twsize());
@@ -3298,7 +3298,7 @@ template<typename T> void r2r_dct(const shape_t &shape,
   const stride_t &stride_in, const stride_t &stride_out, const shape_t &axes,
   int type, const T *data_in, T *data_out, T fct, size_t nthreads=1)
   {
-  if ((type<1) || (type>4)) throw runtime_error("invalid DCT type");
+  if ((type<1) || (type>4)) throw invalid_argument("invalid DCT type");
   if (util::prod(shape)==0) return;
   util::sanity_check(shape, stride_in, stride_out, data_in==data_out, axes);
   cndarr<T> ain(data_in, shape, stride_in);
@@ -3319,7 +3319,7 @@ template<typename T> void r2r_dst(const shape_t &shape,
   const stride_t &stride_in, const stride_t &stride_out, const shape_t &axes,
   int type, const T *data_in, T *data_out, T fct, size_t nthreads=1)
   {
-  if ((type<1) || (type>4)) throw runtime_error("invalid DST type");
+  if ((type<1) || (type>4)) throw invalid_argument("invalid DST type");
   if (util::prod(shape)==0) return;
   util::sanity_check(shape, stride_in, stride_out, data_in==data_out, axes);
   cndarr<T> ain(data_in, shape, stride_in);
diff --git a/pypocketfft.cc b/pypocketfft.cc
index 4137e9e1824a783cbe81b66a7192f4e73d2cff9e..fa57a574b7011427b4f1ff0b84f7c7f01e304d5f 100644
--- a/pypocketfft.cc
+++ b/pypocketfft.cc
@@ -250,7 +250,7 @@ template<typename T> py::array r2r_dct_internal(const py::array &in,
 py::array r2r_dct(const py::array &in, int type, const py::object &axes_,
   int inorm, py::object &out_, size_t nthreads)
   {
-  if ((type<1) || (type>4)) throw runtime_error("invalid DCT type");
+  if ((type<1) || (type>4)) throw invalid_argument("invalid DCT type");
   DISPATCH(in, f64, f32, flong, r2r_dct_internal, (in, axes_, type, inorm,
     out_, nthreads))
   }
@@ -279,7 +279,7 @@ template<typename T> py::array r2r_dst_internal(const py::array &in,
 py::array r2r_dst(const py::array &in, int type, const py::object &axes_,
   int inorm, py::object &out_, size_t nthreads)
   {
-  if ((type<1) || (type>4)) throw runtime_error("invalid DST type");
+  if ((type<1) || (type>4)) throw invalid_argument("invalid DST type");
   DISPATCH(in, f64, f32, flong, r2r_dst_internal, (in, axes_, type, inorm,
     out_, nthreads))
   }
@@ -293,7 +293,7 @@ template<typename T> py::array c2r_internal(const py::array &in,
   shape_t dims_in(copy_shape(in)), dims_out=dims_in;
   if (lastsize==0) lastsize=2*dims_in[axis]-1;
   if ((lastsize/2) + 1 != dims_in[axis])
-    throw runtime_error("bad lastsize");
+    throw invalid_argument("bad lastsize");
   dims_out[axis] = lastsize;
   py::array res = prepare_output<T>(out_, dims_out);
   auto s_in=copy_strides(in);
@@ -355,7 +355,6 @@ template<typename T>py::array complex2hartley(const py::array &in,
   py::gil_scoped_release release;
   simple_iter iin(atmp);
   rev_iter iout(aout, axes);
-  if (iin.remaining()!=iout.remaining()) throw runtime_error("oops");
   while(iin.remaining()>0)
     {
     auto v = atmp[iin.ofs()];