diff --git a/README.md b/README.md
index 419299b..d3443a4 100644
--- a/README.md
+++ b/README.md
@@ -54,9 +54,13 @@ jammy, noble, resolute and trixie on amd64, armhf and arm64.
 * [`control`](./debian/control) — one source stanza and 18 binary packages (`omc`,
   `libomc`, `omedit`, `omshell`, `omnotebook`, `omsimulator`, `omlibrary`, …). Some
   build dependencies carry alternatives (`libhdf5-serial-dev | libhdf5-dev`) because a
-  single control file has to satisfy every distribution in the matrix. Note that `apt`
-  installs the *first* alternative it can, so an alternative is not a way to say
-  "either of these will do" — it only helps where the first one is unavailable.
+  single control file has to satisfy every distribution in the matrix. An alternative
+  only helps where the first one is unavailable: `apt` skips the whole group when any
+  member is already installed or being installed, and its newer solver need not pick
+  the first one at all. A dependency that some distributions cannot satisfy is gated
+  on a build profile instead: `qt6-httpserver-dev <!pkg.openmodelica.nomcp>` (jammy has
+  no QtHttpServer, so apt-build passes `-Ppkg.openmodelica.nomcp` there, and
+  `debian/rules` fails when the profile is off and CMake did not find QtHttpServer).
 * [`rules`](./debian/rules) — a hand-written rules file, *not* the `dh` sequencer. It
   configures and builds the tree itself — with CMake, into `obj-<triplet>/` — and then
   calls each `dh_*` helper explicitly from the `install` and `binary-arch` targets.
@@ -107,9 +111,11 @@ done
 dpkg-source -x "openmodelica_$V-1.dsc"
 rm -rf "openmodelica-$V/debian" && cp -a /buildscripts/debian "openmodelica-$V/debian"
 sed -i -e "s/@REV@/$V/" -e "s/@TIME@/$(date -R)/" "openmodelica-$V/debian/changelog"
-cd "openmodelica-$V" && dpkg-buildpackage -rfakeroot -b -j"$(nproc)"
+cd "openmodelica-$V" && dpkg-buildpackage -rfakeroot -b -j"$(nproc)" -Ppkg.openmodelica.nomcp
 ```
 
+Drop `-Ppkg.openmodelica.nomcp` for any distribution newer than jammy.
+
 The first run takes hours. Afterwards `build-stamp` is cached, so re-running only
 `fakeroot debian/rules binary-arch` after another `debian/` tweak takes minutes.
 
diff --git a/debian/control b/debian/control
index e98dce0..ec7c0f8 100644
--- a/debian/control
+++ b/debian/control
@@ -33,8 +33,8 @@ Build-Depends: debhelper-compat (= 13),
  qt6-shadertools-dev | libqt6shadertools6-dev,
 # Qt links libGL.so by absolute path; only jammy's qt6-base-dev omits it
  libgl-dev,
-# QtHttpServer needs Qt 6.4; OMEdit builds without the MCP server on jammy
- qt6-httpserver-dev | qt6-base-dev,
+# QtHttpServer needs Qt 6.4: jammy builds with -Ppkg.openmodelica.nomcp
+ qt6-httpserver-dev <!pkg.openmodelica.nomcp>,
  flex,
  bison,
  liblpsolve55-dev (>= 5.5.0.10),
diff --git a/debian/rules b/debian/rules
index 3da4848..fdea03e 100755
--- a/debian/rules
+++ b/debian/rules
@@ -61,6 +61,10 @@ build-stamp:
 	-DOM_RUST_RESULT_READERS=ON \
 	-DOM_RUST_RESULT_WRITERS=ON \
 	-DOM_ENABLE_RUST_SIM_RUNTIME=ON
+ifeq (,$(filter pkg.openmodelica.nomcp,$(DEB_BUILD_PROFILES)))
+	grep -q '^Qt6HttpServer_DIR:PATH=/' $(BUILD)/CMakeCache.txt || \
+	  { echo 'QtHttpServer not found; build with -Ppkg.openmodelica.nomcp to drop the MCP server' >&2; exit 1; }
+endif
 	cmake --build $(BUILD) $(BUILDFLAGS)
 	touch build-stamp