diff --git a/thirdparty/CMakeLists.txt b/thirdparty/CMakeLists.txt
index 7b70080e67d23ef40a7be0777ab619722ace2446..b12a06fad643a97bfcb6910ed9a36a6fb2086db0 100644
--- a/thirdparty/CMakeLists.txt
+++ b/thirdparty/CMakeLists.txt
@@ -113,7 +113,7 @@ target_include_directories(blosc INTERFACE
     blosc
     SZ/sz/include
     )
-target_compile_definitions(blosc PRIVATE HAVE_LZ4 HAVE_SNAPPY HAVE_ZLIB HAVE_ZSTD)
+target_compile_definitions(blosc PRIVATE HAVE_LZ4 HAVE_SNAPPY HAVE_ZLIB HAVE_ZSTD HAVE_UNISTD_H)
 if(OpenMP_FOUND)
     target_link_libraries(blosc PRIVATE OpenMP::OpenMP_C OpenMP::OpenMP_CXX)
-endif()
\ No newline at end of file
+endif()