--- a/src/runtime/src/coreclr/debug/createdump/crashinfounix.cpp
+++ b/src/runtime/src/coreclr/debug/createdump/crashinfounix.cpp
@@ -469,7 +469,7 @@ CrashInfo::ReadProcessMemory(void* address, void* buffer, size_t size, size_t* r
         // performance optimization.
         m_canUseProcVmReadSyscall = false;
         assert(m_fdMem != -1);
-        *read = pread64(m_fdMem, buffer, size, (off64_t)address);
+        *read = pread(m_fdMem, buffer, size, (off_t)address);
     }
 
     if (*read == (size_t)-1)
--- a/src/runtime/src/coreclr/debug/createdump/crashinfo.cpp
+++ b/src/runtime/src/coreclr/debug/createdump/crashinfo.cpp
@@ -760,7 +760,7 @@ CrashInfo::PageMappedToPhysicalMemory(uint64_t start)
         }
 
         uint64_t pagemapOffset = (start / PAGE_SIZE) * sizeof(uint64_t);
-        uint64_t seekResult = lseek64(m_fdPagemap, (off64_t) pagemapOffset, SEEK_SET);
+        uint64_t seekResult = lseek(m_fdPagemap, (off_t) pagemapOffset, SEEK_SET);
         if (seekResult != pagemapOffset)
         {
             int seekErrno = errno;