diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6cc9fceaf5..605ba0b612 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -409,7 +409,7 @@ install(DIRECTORY include/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 #=============================
 # write the dl_open Makefile
 #=============================
-file(WRITE share/Makefile"
+file(WRITE share/Makefile "
 # Makefile to build dynamic sources for OpenMC
 # this assumes that your source sampling filename is
 # source_sampling.cpp