diff --git a/Modules/FindHDF5.cmake b/Modules/FindHDF5.cmake
index 65a825d912..36cd335496 100644
--- a/Modules/FindHDF5.cmake
+++ b/Modules/FindHDF5.cmake
@@ -352,7 +352,7 @@ macro( _HDF5_parse_compile_line
       list(APPEND ${include_paths} "${CMAKE_MATCH_1}")
     elseif("${arg}" MATCHES "^-D(.*)$")
       # compile definition
-      list(APPEND ${definitions} "${CMAKE_MATCH_1}")
+      list(APPEND ${definitions} "-D${CMAKE_MATCH_1}")
     elseif("${arg}" MATCHES "^-L(.*)$")
       # library search path
       list(APPEND ${library_paths} "${CMAKE_MATCH_1}")