diff --git a/source/adios2/helper/mpidummy.cpp b/source/adios2/helper/mpidummy.cpp
index 03d32fd5b8..618a0ce721 100644
--- a/source/adios2/helper/mpidummy.cpp
+++ b/source/adios2/helper/mpidummy.cpp
@@ -299,77 +299,6 @@ int MPI_Wait(MPI_Request * /*request*/, MPI_Status * /*status*/)
     RETURN_CHECK(MPI_SUCCESS);
 }
 
-#ifndef ADIOS2_HAVE_MPI
-
-int MPI_File_open(MPI_Comm /*comm*/, const char *filename, int amode,
-                  MPI_Info /*info*/, MPI_File *fh)
-{
-    std::string mode;
-    if (amode | MPI_MODE_RDONLY)
-    {
-        mode += "r";
-    }
-    if (amode | MPI_MODE_WRONLY)
-    {
-        mode += "w";
-    }
-    if (amode | MPI_MODE_APPEND)
-    {
-        mode += "a";
-    }
-    mode += "b";
-
-    *fh = std::fopen(filename, mode.c_str());
-    if (!*fh)
-    {
-        return -1;
-    }
-    RETURN_CHECK(MPI_SUCCESS);
-}
-
-int MPI_File_close(MPI_File *fh) { return fclose(*fh); }
-
-int MPI_File_get_size(MPI_File fh, MPI_Offset *size)
-{
-    long curpos = std::ftell(fh);
-    fseek(fh, 0, SEEK_END); // go to end, returned is the size in bytes
-    long endpos = std::ftell(fh);
-    std::fseek(fh, curpos, SEEK_SET); // go back where we were
-    *size = static_cast<MPI_Offset>(endpos);
-    // printf("MPI_File_get_size: fh=%d, size=%lld\n", fh, *size);
-    RETURN_CHECK(MPI_SUCCESS);
-}
-
-int MPI_File_read(MPI_File fh, void *buf, int count, MPI_Datatype datatype,
-                  MPI_Status *status)
-{
-    // FIXME: int count can read only 2GB (*datatype size) array at max
-    size_t bytes_to_read = static_cast<size_t>(count) * datatype;
-    size_t bytes_read;
-    bytes_read = std::fread(buf, 1, bytes_to_read, fh);
-    if (bytes_read != bytes_to_read)
-    {
-        return -2;
-    }
-    *status = bytes_read;
-    // printf("MPI_File_read: fh=%d, count=%d, typesize=%d, bytes read=%lld\n",
-    // fh, count, datatype, *status);
-    RETURN_CHECK(MPI_SUCCESS);
-}
-
-int MPI_File_seek(MPI_File fh, MPI_Offset offset, int whence)
-{
-    return std::fseek(fh, offset, whence) == MPI_SUCCESS;
-}
-
-int MPI_Get_count(const MPI_Status *status, MPI_Datatype, int *count)
-{
-    *count = static_cast<int>(*status);
-    RETURN_CHECK(MPI_SUCCESS);
-}
-
-#endif
-
 double MPI_Wtime()
 {
     std::chrono::duration<double> now =
diff --git a/source/adios2/helper/mpidummy.h b/source/adios2/helper/mpidummy.h
index 6415ada89a..ba2e8f69a7 100644
--- a/source/adios2/helper/mpidummy.h
+++ b/source/adios2/helper/mpidummy.h
@@ -24,10 +24,8 @@
 typedef int MPI_Comm;
 typedef uint64_t MPI_Status;
 typedef uint64_t MPI_Request;
-typedef FILE *MPI_File;
 typedef int MPI_Info;
 typedef int MPI_Datatype;
-typedef long int MPI_Offset;
 typedef int MPI_Fint;
 typedef int MPI_Op;
 
@@ -168,15 +166,6 @@ int MPI_Wait(MPI_Request *request, MPI_Status *status);
 
 int MPI_Type_size(MPI_Datatype datatype, int *size);
 
-int MPI_File_open(MPI_Comm comm, const char *filename, int amode, MPI_Info info,
-                  MPI_File *fh);
-int MPI_File_close(MPI_File *fh);
-int MPI_File_get_size(MPI_File fh, MPI_Offset *size);
-int MPI_File_read(MPI_File fh, void *buf, int count, MPI_Datatype datatype,
-                  MPI_Status *status);
-int MPI_File_seek(MPI_File fh, MPI_Offset offset, int whence);
-
-int MPI_Get_count(const MPI_Status *status, MPI_Datatype datatype, int *count);
 int MPI_Comm_split(MPI_Comm comm, int color, int key, MPI_Comm *comm_out);
 
 int MPI_Get_processor_name(char *name, int *resultlen);