diff --git a/Makefile.top b/Makefile.top
index 22f61e682e3da20e41faeea1b47a7ab1006e3c18..f78eb246896f541c3952b1f030d7d57b21aac3b2 100644
--- a/Makefile.top
+++ b/Makefile.top
@@ -60,7 +60,7 @@ endif
 
 define COMMON_REGISTER
 
-$(1): $$(patsubst %,$(O)/.objs/$(3)%.o,$$($(2)_MODULES))
+$(1): $$(patsubst %,$(O)/.objs/$(3)%.o,$$($(2)_MODULES) $$($(2)_MODULES_3RDPARTY))
 $(1): CFLAGS_ALL += $$($(2)_CFLAGS) $$(foreach CONFIG,$$($(2)_PKG_CONFIGS),$$(shell pkg-config --cflags $$(CONFIG))) $$(foreach CONFIG,$$($(2)_EXE_CONFIGS),$$(shell $$(CONFIG)-config --cflags))
 $(1): LDFLAGS_ALL += $$($(2)_LDFLAGS) $$(foreach CONFIG,$$($(2)_PKG_CONFIGS),$$(shell pkg-config --libs $$(CONFIG))) $$(foreach CONFIG,$$($(2)_EXE_CONFIGS),$$(shell $$(CONFIG)-config --libs))
 ifdef STATIC_GLOBAL
diff --git a/buildsystem.txt b/buildsystem.txt
index 61e800a367f9b477885f87e143fee74603db6802..d2e08f34b87020c622506d0ac1e830f7441b83a9 100644
--- a/buildsystem.txt
+++ b/buildsystem.txt
@@ -60,7 +60,7 @@ following code:
   # List sources. Without the .c at the end or path. The input files
   # don't need to be unique, so there can be another main.c in other
   # directory. You don't list the headers.
-  hello_world_SOURCES := \
+  hello_world_MODULES := \
     main \
     hello \
     world
@@ -77,12 +77,17 @@ following code:
   # the dependencies against the local libraries can be tracked.
   hello_world_LOCAL_LIBS := libworld
 
-Only the `_SOURCES` variable is mandatory. You can create a shared
+Only the `_MODULES` variable is mandatory. You can create a shared
 library the same way, it is only appended to `LIBRARIES` instead to
 `BINARIES`. Also, if you want to let the build system know about a
 binary, but not build it by default (needed for the `check` target,
 for example), you can use `BINARIES_NOTARGET`.
 
+The variable `_MODULES_3RDPARTY` is similar to `_MODULES`, but is
+excluded from some checks (like `cppcheck`). The idea is that
+third-party software may be included in the compilation, but nobody
+wants to fix their style.
+
 You can also generate documentation (`html` from the `txt` by
 asciidoc). It has no variables to influence it and you append them to
 the `DOCS` variable.