diff --git a/src/python/jw/pkg/cmds/projects/CmdBuild.py b/src/python/jw/pkg/cmds/projects/CmdBuild.py
index 3a29b899..e92a5b22 100644
--- a/src/python/jw/pkg/cmds/projects/CmdBuild.py
+++ b/src/python/jw/pkg/cmds/projects/CmdBuild.py
@@ -62,6 +62,14 @@ class CmdBuild(Cmd):  # export
                 'comma or space separated'
             )
         )
+        parser.add_argument(
+            '--pkg-relations',
+            default = 'requires',
+            help = (
+                'Relations between packages to take into consideration for build, '
+                'comma or space separated'
+            )
+        )
         parser.add_argument(
             '--env-reinit',
             action = 'store_true',
@@ -103,7 +111,11 @@ class CmdBuild(Cmd):  # export
             )
 
         @lru_cache(maxsize = None)
-        def read_deps(cur: str, dep_flavour: str) -> list[str]:
+        def read_deps(
+            cur: str,
+            dep_flavour: str,
+            relations: tuple[str, ...],
+        ) -> Iterable[str]:
             # dep cache doesn't make a difference at all
             if dep_flavour in dep_cache:
                 if cur in dep_cache[dep_flavour]:
@@ -113,13 +125,13 @@ class CmdBuild(Cmd):  # export
 
             ret = self.app.get_project_refs(
                 [cur],
-                ['pkg.requires.jw'],
+                [f'pkg.{rel}.jw' for rel in relations],
                 dep_flavour,
                 scope = Scope.Subtree,
                 add_self = False,
                 names_only = True,
             )
-            log(DEBUG, f'Prerequisites: {" ".join(ret)}')
+            log(DEBUG, f'Prerequisites ({"/".join(relations)}): {" ".join(ret)}')
             if cur in ret:
                 ret.remove(cur)
 
@@ -134,6 +146,7 @@ class CmdBuild(Cmd):  # export
         def add_dep_tree(
             cur: str,
             dep_flavours: Iterable[str],
+            relations: tuple[str, ...],
             tree: DepNode,
             all_deps: set[str],
         ) -> int:
@@ -145,9 +158,9 @@ class CmdBuild(Cmd):  # export
             all_deps.add(cur)
             for t in dep_flavours:
                 log(DEBUG, f'Checking deps of type "{t}"')
-                deps.update(read_deps(cur, t))
+                deps.update(read_deps(cur, t, relations))
             for d in deps:
-                add_dep_tree(d, dep_flavours, tree, all_deps)
+                add_dep_tree(d, dep_flavours, relations, tree, all_deps)
             tree[cur] = deps
             return len(deps)
 
@@ -158,9 +171,10 @@ class CmdBuild(Cmd):  # export
         ) -> int:
             all_deps: set[str] = set()
             dep_tree: DepNode = {}
+            relations = tuple(re.split(r'[,\s]+', args.pkg_relations))
             for m in modules:
                 log(DEBUG, f'--- Adding dependency tree of module "{m}"')
-                add_dep_tree(m, dep_flavours, dep_tree, all_deps)
+                add_dep_tree(m, dep_flavours, relations, dep_tree, all_deps)
             while len(all_deps):
                 # Find any leaf, deterministically: sorted, so that the
                 # order is reproducible across runs
diff --git a/test/integration/jw-pkg/help/test-expected.txt b/test/integration/jw-pkg/help/test-expected.txt
index 8560a11c..c7b895c9 100644
--- a/test/integration/jw-pkg/help/test-expected.txt
+++ b/test/integration/jw-pkg/help/test-expected.txt
@@ -256,7 +256,8 @@ Available subcommands of projects:
     tmpl-dir            Print directory containing templates of a given module
 ============= Running: jw-pkg.py -t ../../../.. --log-level info projects build --help
 usage: jw-pkg.py projects build [-h] [--exclude EXCLUDE] [-n] [-O] [-I]
-                                [--dep-flavours DEP_FLAVOURS] [--env-reinit]
+                                [--dep-flavours DEP_FLAVOURS]
+                                [--pkg-relations PKG_RELATIONS] [--env-reinit]
                                 [--env-keep ENV_KEEP]
                                 target modules [modules ...]
 
@@ -279,6 +280,10 @@ options:
   --dep-flavours DEP_FLAVOURS
                         Dependency flavours to take into consideration for
                         build, comma or space separated (default: auto)
+  --pkg-relations PKG_RELATIONS
+                        Relations between packages to take into consideration
+                        for build, comma or space separated (default:
+                        requires)
   --env-reinit          Source /etc/profile before each build step. Discard
                         environment unless --env-keep is specified (default:
                         False)