diff --git a/v-hacd.spec b/v-hacd.spec
index 3b26bd4..3016be6 100644
--- a/v-hacd.spec
+++ b/v-hacd.spec
@@ -25,13 +25,12 @@ Source2:        TestVHACD.1
 # Very trivial OBJ mesh file from mcut, which is LGPL-3.0-only
 Source3:        https://github.com/cutdigital/mcut/raw/refs/tags/v1.3.0/tutorials/BasicCmdLineApp/data/cube.obj
 
+BuildSystem:    cmake
+
 # https://fedoraproject.org/wiki/Changes/EncourageI686LeafRemoval
 ExcludeArch:    %{ix86}
 
 BuildRequires:  gcc-c++
-BuildRequires:  cmake
-# Our choice; the make backend would work just fine.
-BuildRequires:  ninja-build
 
 %global common_description %{expand:
 The V-HACD library decomposes a 3D surface into a set of “near” convex parts.
@@ -67,7 +66,6 @@ Summary:        Development files for V-HACD
 # The MIT-licensed app/wavefront.{h,cpp} do not contribute to this subpackage.
 License:        BSD-3-Clause
 
-
 BuildArch:      noarch
 
 # https://docs.fedoraproject.org/en-US/packaging-guidelines/#_packaging_header_only_libraries
@@ -96,30 +94,25 @@ library. Currently, this means TestVHACD; despite the name, this tool has
 general utility beyond testing.
 
 
-%prep
-%autosetup -p1
+%conf -p
+cd app
 
 
-%build
-pushd app >/dev/null
-%cmake -GNinja
-%cmake_build
-popd >/dev/null
+%build -p
+cd app
 
 
 %install
-pushd app >/dev/null
+install -D --preserve-timestamps --mode=0644 \
+    --target='%{buildroot}%{_includedir}' 'include/VHACD.h'
+install -D --preserve-timestamps --mode=0644 \
+    --target='%{buildroot}%{_mandir}/man1' '%{SOURCE2}'
+
+cd app
 # There are currently no install targets in app/CMakeLists.txt, so
 # %%cmake_install will not work. We install the executable manually instead.
 install -D --preserve-timestamps \
     --target='%{buildroot}%{_bindir}' '%{_vpath_builddir}/TestVHACD'
-popd >/dev/null
-
-install -D --preserve-timestamps --mode=0644 \
-    --target='%{buildroot}%{_includedir}' 'include/VHACD.h'
-
-install -D --preserve-timestamps --mode=0644 \
-    --target='%{buildroot}%{_mandir}/man1' '%{SOURCE2}'
 
 
 %check