--- modules/modperl/CMakeLists.txt.orig	2022-07-15 15:39:37 UTC
+++ modules/modperl/CMakeLists.txt
@@ -53,7 +53,7 @@ if(WANT_PERL)
 		"-I${PROJECT_BINARY_DIR}/include"
 		"-I${PROJECT_SOURCE_DIR}/include"
 		"-I${CMAKE_CURRENT_SOURCE_DIR}/.."
 		"-I${CMAKE_CURRENT_SOURCE_DIR}/include"
-		-DZNC_EXPORT_LIB_EXPORT
+		"-DZNC_EXPORT_LIB_EXPORT="
 		-outdir "${CMAKE_CURRENT_BINARY_DIR}"
 		-o "${CMAKE_CURRENT_BINARY_DIR}/modperl_biglib.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/modperl.i"
