diff --git a/CMakeLists.txt b/CMakeLists.txt
index 09e366ff..763c6521 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -977,6 +977,7 @@ if (UNIX)
 	# TODO: Fix this on Windows.
 	message("Generating API documentation")
 	file(GLOB C_FILES "${PROJECT_SOURCE_DIR}/lib/*.c")
+	list(SORT C_FILES)
 	execute_process(COMMAND "${CMAKE_COMMAND}" -E make_directory "${PROJECT_BINARY_DIR}/doc/")
 
 	execute_process(