diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -171,12 +171,18 @@
 file(MAKE_DIRECTORY "${OBJ_DIR}")
 set(BUILD_HEADER "${OBJ_DIR}/build.h")
 add_custom_command(
-	OUTPUT "${BUILD_HEADER}"
+	OUTPUT
+		"${BUILD_HEADER}"
+		__always_build_header.h
 	COMMAND
 		"${CMAKE_SOURCE_DIR}/share/genbuild.sh"
 		"${BUILD_HEADER}"
 		"${CMAKE_SOURCE_DIR}"
 )
+# HACK: Ensure that build.h is always generated.
+# Because the __always_build_header.h file doesn't exist, cmake will always try
+# to generate it as it is a dependency for the ALL target below.
+add_custom_target(always_build_header ALL DEPENDS __always_build_header.h)
 
 # Because the Bitcoin ABc source code is disorganised, we
 # end up with a bunch of libraries without any apparent
@@ -207,9 +213,6 @@
 	utilstrencodings.cpp
 	utiltime.cpp
 	util/bytevectorhash.cpp
-
-	# obj/build.h
-	${BUILD_HEADER}
 )
 
 target_compile_definitions(util PUBLIC HAVE_CONFIG_H HAVE_BUILD_INFO)