diff --git a/fortran/src/CMakeLists.txt b/fortran/src/CMakeLists.txt
index 1b23c94a976..855310879ef 100644
--- a/fortran/src/CMakeLists.txt
+++ b/fortran/src/CMakeLists.txt
@@ -406,7 +406,7 @@ if (BUILD_STATIC_LIBS)
 endif ()
 
 if (BUILD_SHARED_LIBS)
-  if(WIN32)
+  if(MSVC)
       set(DLLDEF ${HDF5_F90_SRC_BINARY_DIR}/hdf5_fortrandll.def)
   else()
       set(DLLDEF "")
diff --git a/hl/fortran/src/CMakeLists.txt b/hl/fortran/src/CMakeLists.txt
index f225eb8f3b4..a9361ad5029 100644
--- a/hl/fortran/src/CMakeLists.txt
+++ b/hl/fortran/src/CMakeLists.txt
@@ -193,7 +193,7 @@ if (BUILD_STATIC_LIBS)
   add_dependencies(${HDF5_HL_F90_LIB_TARGET} H5HLgen)
 endif ()
 if (BUILD_SHARED_LIBS)
-  if(WIN32)
+  if(MSVC)
       set(DLLDEF ${HDF5_HL_F90_SRC_BINARY_DIR}/hdf5_hl_fortrandll.def)
   else()
       set(DLLDEF "")