diff --git a/local/recipes/dev/libclc/recipe.toml b/local/recipes/dev/libclc/recipe.toml
index 7e222228d5..aac562a1a1 100644
--- a/local/recipes/dev/libclc/recipe.toml
+++ b/local/recipes/dev/libclc/recipe.toml
@@ -107,7 +107,16 @@ export CFLAGS="$_SAVED_CFLAGS"
 export CXXFLAGS="$_SAVED_CXXFLAGS"
 export CPPFLAGS="$_SAVED_CPPFLAGS"
 
-# Source dir is the path_in_repo subdir of the cloned llvm-project.
+# Source dir is the path_in_repo subdir of the cloned llvm-project. This
+# cookbook does not extract path_in_repo into COOKBOOK_SOURCE — it clones the
+# whole llvm-project there — so CMake was pointed at the repo root and failed
+# with "source directory does not appear to contain CMakeLists.txt". Descend
+# into the libclc subdir when the whole repo was cloned (mirrors how the clang21
+# recipe does COOKBOOK_SOURCE/clang); if path_in_repo already left the subdir at
+# the root, use it as-is.
+if [ -f "${COOKBOOK_SOURCE}/libclc/CMakeLists.txt" ]; then
+    COOKBOOK_SOURCE="${COOKBOOK_SOURCE}/libclc"
+fi
 "${COOKBOOK_CMAKE}" "${COOKBOOK_SOURCE}" "${COOKBOOK_CMAKE_FLAGS[@]}"
 "${COOKBOOK_NINJA}" -j"${COOKBOOK_MAKE_JOBS}"
 DESTDIR="${COOKBOOK_STAGE}/stage" "${COOKBOOK_NINJA}" install