diff --git a/crates/fbuild-build-engine/src/build_info.rs b/crates/fbuild-build-engine/src/build_info.rs
index e7c1f19b..5f219ee0 100644
--- a/crates/fbuild-build-engine/src/build_info.rs
+++ b/crates/fbuild-build-engine/src/build_info.rs
@@ -812,7 +812,9 @@ mod tests {
     fn find_build_info_walks_up_from_elf_dir() {
         let tmp = tempfile::TempDir::new().unwrap();
         let project = tmp.path();
-        let build_dir = project.join(".fbuild").join("build").join("uno");
+        let build_dir = fbuild_paths::get_project_fbuild_dir(project)
+            .join(fbuild_paths::BUILD_DIR_NAME)
+            .join("uno");
         std::fs::create_dir_all(&build_dir).unwrap();
         // Emit at the project root (where platformio.ini would live).
         let info = sample_info();
diff --git a/crates/fbuild-build-engine/src/compile_database/tests/clang.rs b/crates/fbuild-build-engine/src/compile_database/tests/clang.rs
index 724c6b1e..c0ab5912 100644
--- a/crates/fbuild-build-engine/src/compile_database/tests/clang.rs
+++ b/crates/fbuild-build-engine/src/compile_database/tests/clang.rs
@@ -7,6 +7,25 @@ use crate::compile_database::{
     CompileDatabase, CompileEntry, TargetArchitecture, translate_flags_for_clang,
 };
 
+/// Fixture build directory, assembled from the canonical segments so these
+/// tests cannot describe a layout the resolver no longer produces
+/// (FastLED/fbuild#1349).
+fn fixture_dir() -> String {
+    format!(
+        "/project/{}/{}/env/src",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    )
+}
+
+fn fixture_src() -> String {
+    format!("{}/sketch.ino.cpp", fixture_dir())
+}
+
+fn fixture_obj() -> String {
+    format!("{}/sketch.ino.cpp.o", fixture_dir())
+}
+
 #[test]
 fn test_target_triples() {
     assert_eq!(TargetArchitecture::Xtensa.target_triple(), "xtensa-esp-elf");
@@ -260,13 +279,13 @@ fn ino_cpp_template_entry() -> CompileEntry {
             "--target=xtensa-esp-elf".to_string(),
             "-Isrc".to_string(),
             "-c".to_string(),
-            "/project/.fbuild/build/env/src/sketch.ino.cpp".to_string(),
+            fixture_src().as_str().to_string(),
             "-o".to_string(),
-            "/project/.fbuild/build/env/src/sketch.ino.cpp.o".to_string(),
+            fixture_obj().as_str().to_string(),
         ],
         directory: "/project".to_string(),
-        file: "/project/.fbuild/build/env/src/sketch.ino.cpp".to_string(),
-        output: Some("/project/.fbuild/build/env/src/sketch.ino.cpp.o".to_string()),
+        file: fixture_src().as_str().to_string(),
+        output: Some(fixture_obj().as_str().to_string()),
     }
 }
 
@@ -277,7 +296,7 @@ fn test_swap_ino_entries_for_raw_replaces_generated_entry() {
 
     let ino_preludes = vec![(
         PathBuf::from("/project/src/sketch.ino"),
-        PathBuf::from("/project/.fbuild/build/env/src/sketch.ino.prelude.h"),
+        PathBuf::from(format!("{}/sketch.ino.prelude.h", fixture_dir())),
     )];
     let swapped = db.swap_ino_entries_for_raw(&ino_preludes);
 
@@ -298,7 +317,7 @@ fn test_swap_ino_entries_for_raw_replaces_generated_entry() {
         .unwrap();
     assert_eq!(
         entry.arguments[include_idx + 1],
-        "/project/.fbuild/build/env/src/sketch.ino.prelude.h"
+        format!("{}/sketch.ino.prelude.h", fixture_dir()).as_str()
     );
     assert!(
         entry
@@ -323,11 +342,11 @@ fn test_swap_ino_entries_for_raw_multi_tab() {
     let ino_preludes = vec![
         (
             PathBuf::from("/project/src/main.ino"),
-            PathBuf::from("/project/.fbuild/build/env/src/main.ino.prelude.h"),
+            PathBuf::from(format!("{}/main.ino.prelude.h", fixture_dir())),
         ),
         (
             PathBuf::from("/project/src/a_tab.ino"),
-            PathBuf::from("/project/.fbuild/build/env/src/a_tab.ino.prelude.h"),
+            PathBuf::from(format!("{}/a_tab.ino.prelude.h", fixture_dir())),
         ),
     ];
     let swapped = db.swap_ino_entries_for_raw(&ino_preludes);
@@ -372,7 +391,7 @@ fn test_swap_ino_entries_for_raw_no_generated_entry_leaves_db_untouched() {
 
     let ino_preludes = vec![(
         PathBuf::from("/project/src/sketch.ino"),
-        PathBuf::from("/project/.fbuild/build/env/src/sketch.ino.prelude.h"),
+        PathBuf::from(format!("{}/sketch.ino.prelude.h", fixture_dir())),
     )];
     let swapped = db.swap_ino_entries_for_raw(&ino_preludes);
     assert_eq!(swapped.entries.len(), 1);
diff --git a/crates/fbuild-build-engine/src/compile_database/tests/generate.rs b/crates/fbuild-build-engine/src/compile_database/tests/generate.rs
index 4d19c3f7..2f19970b 100644
--- a/crates/fbuild-build-engine/src/compile_database/tests/generate.rs
+++ b/crates/fbuild-build-engine/src/compile_database/tests/generate.rs
@@ -355,13 +355,21 @@ fn test_generate_entries_file_is_source_not_build() {
         &[],
         &[],
         &[PathBuf::from("/project/src/main.cpp")],
-        Path::new("/project/.fbuild/build/esp32/src"),
+        Path::new(&format!(
+            "/project/{}/{}/esp32/src",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        )),
         Path::new("/project"),
     );
     assert_eq!(entries[0].file, "/project/src/main.cpp");
     // Output should be in the build dir
     assert!(
-        entries[0].output.as_ref().unwrap().contains(".fbuild"),
+        entries[0]
+            .output
+            .as_ref()
+            .unwrap()
+            .contains(fbuild_paths::FBUILD_DIR_NAME),
         "output should be in build dir: {:?}",
         entries[0].output
     );
@@ -437,7 +445,11 @@ fn test_generate_entries_include_flags_preserved_verbatim() {
     // source-tree paths, not build-dir paths.
     let include_flags = vec![
         "-I/project/src".to_string(), // source tree ✓
-        "-I/home/user/.fbuild/build/esp32/libs/fastled/src".to_string(), // cache path ✗
+        format!(
+            "-I/home/user/{}/{}/esp32/libs/fastled/src",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        ), // cache path ✗
         "-I/framework/cores/esp32".to_string(), // framework ✓
     ];
     let entries = generate_entries(
diff --git a/crates/fbuild-build-engine/src/compiler_tests.rs b/crates/fbuild-build-engine/src/compiler_tests.rs
index 05fa8d5d..96a4a32a 100644
--- a/crates/fbuild-build-engine/src/compiler_tests.rs
+++ b/crates/fbuild-build-engine/src/compiler_tests.rs
@@ -35,7 +35,7 @@ async fn compile_path_contract_pairs_cwd_and_output_arg_for_282() {
     // Workspace shape mirrors CI: <project>/.fbuild/build/<env>/quick/core
     let workspace = tmp_canon.join("proj_for_282");
     let core = workspace
-        .join(".fbuild")
+        .join(fbuild_paths::FBUILD_DIR_NAME)
         .join("build")
         .join("x")
         .join("quick")
@@ -322,7 +322,11 @@ fn test_needs_rebuild_resolves_relative_depfile_deps_against_workspace() {
     let tmp = tempfile::TempDir::new().unwrap();
     let ws = tmp.path();
     let src_dir = ws.join("src");
-    let build_dir = ws.join(".fbuild/build/demo/release/src");
+    let build_dir = ws.join(format!(
+        "{}/{}/demo/release/src",
+        fbuild_paths::FBUILD_DIR_NAME,
+        fbuild_paths::BUILD_DIR_NAME
+    ));
     std::fs::create_dir_all(&src_dir).unwrap();
     std::fs::create_dir_all(&build_dir).unwrap();
 
@@ -337,7 +341,11 @@ fn test_needs_rebuild_resolves_relative_depfile_deps_against_workspace() {
     // compile cwd is the workspace root.
     std::fs::write(
         &dep,
-        ".fbuild/build/demo/release/src/main.cpp.o: src/main.cpp src/config.h\n",
+        format!(
+            "{}/{}/demo/release/src/main.cpp.o: src/main.cpp src/config.h\n",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        ),
     )
     .unwrap();
     std::thread::sleep(std::time::Duration::from_millis(20));
@@ -438,8 +446,12 @@ fn test_build_rebuild_signature_for_workspace_outside_paths_keep_legacy_normaliz
     // to the project-independent normalization — unchanged behavior.
     let tmp_a = tempfile::tempdir().unwrap();
     let tmp_b = tempfile::tempdir().unwrap();
-    let global_a = tmp_a.path().join(".fbuild/cache/framework/cores/arduino");
-    let global_b = tmp_b.path().join(".fbuild/cache/framework/cores/arduino");
+    let cache_rel = format!(
+        "{}/cache/framework/cores/arduino",
+        fbuild_paths::FBUILD_DIR_NAME
+    );
+    let global_a = tmp_a.path().join(&cache_rel);
+    let global_b = tmp_b.path().join(&cache_rel);
     let ws_a = tmp_a.path().join("proj-a");
     let ws_b = tmp_b.path().join("other-name-proj-b");
     std::fs::create_dir_all(&ws_a).unwrap();
@@ -501,7 +513,10 @@ fn test_build_rebuild_signature_ignores_absolute_compiler_path() {
         &[],
     );
     let sig_b = build_rebuild_signature(
-        Path::new("/home/runner/.fbuild/packages/toolchain-atmelavr/bin/avr-gcc"),
+        Path::new(&format!(
+            "/home/runner/{}/packages/toolchain-atmelavr/bin/avr-gcc",
+            fbuild_paths::FBUILD_DIR_NAME
+        )),
         &flags,
         &[],
         &[],
@@ -536,11 +551,17 @@ fn test_build_rebuild_signature_changes_when_compiler_name_changes() {
 fn test_build_rebuild_signature_ignores_attached_include_root() {
     let flags_a = vec![
         "-I/tmp/ws-a/project/include".to_string(),
-        "-I/home/runner/.fbuild/packages/framework-arduinoavr/cores/arduino".to_string(),
+        format!(
+            "-I/home/runner/{}/packages/framework-arduinoavr/cores/arduino",
+            fbuild_paths::FBUILD_DIR_NAME
+        ),
     ];
     let flags_b = vec![
         "-I/tmp/ws-b/project/include".to_string(),
-        "-I/Users/runner/.fbuild/packages/framework-arduinoavr/cores/arduino".to_string(),
+        format!(
+            "-I/Users/runner/{}/packages/framework-arduinoavr/cores/arduino",
+            fbuild_paths::FBUILD_DIR_NAME
+        ),
     ];
 
     let sig_a = build_rebuild_signature(
diff --git a/crates/fbuild-build-engine/src/linker.rs b/crates/fbuild-build-engine/src/linker.rs
index 9f303d1f..763b1cf1 100644
--- a/crates/fbuild-build-engine/src/linker.rs
+++ b/crates/fbuild-build-engine/src/linker.rs
@@ -606,8 +606,13 @@ mod tests {
     /// FastLED/fbuild#1267, FastLED/FastLED#3867.
     #[test]
     fn link_cwd_is_absolute_output_dir_when_all_paths_absolute() {
-        let out = abs("proj/.fbuild/build/release");
-        let paths = [abs("proj/.fbuild/build/release/sketch.o"), abs("sdk/ld")];
+        let rel = format!(
+            "proj/{}/{}/release",
+            fbuild_paths::FBUILD_DIR_NAME,
+            fbuild_paths::BUILD_DIR_NAME
+        );
+        let out = abs(&rel);
+        let paths = [abs(&format!("{rel}/sketch.o")), abs("sdk/ld")];
         assert_eq!(
             link_cwd_for(&out, &paths),
             Some(out.as_path()),
diff --git a/dylints/ban_raw_fbuild_path/Cargo.toml b/dylints/ban_raw_fbuild_path/Cargo.toml
index 86bb1170..9da0f296 100644
--- a/dylints/ban_raw_fbuild_path/Cargo.toml
+++ b/dylints/ban_raw_fbuild_path/Cargo.toml
@@ -3,7 +3,7 @@ name = "ban_raw_fbuild_path"
 # Bump the version to bust the dylint .so cache when allowlist.txt
 # changes (setup-soldr's dylint-cache key hashes the manifest but not
 # src/allowlist.txt). Same convention ban_manual_slash_normalize follows.
-version = "0.1.5"
+version = "0.1.6"
 description = "Ban raw '.fbuild' path literals outside fbuild-paths"
 edition = "2021"
 publish = false
diff --git a/dylints/ban_raw_fbuild_path/src/allowlist.txt b/dylints/ban_raw_fbuild_path/src/allowlist.txt
index d9d01be6..2de366a3 100644
--- a/dylints/ban_raw_fbuild_path/src/allowlist.txt
+++ b/dylints/ban_raw_fbuild_path/src/allowlist.txt
@@ -38,11 +38,6 @@ crates/fbuild-cli/src/cli/args.rs
 # Each line below is a file that spells `.fbuild` by hand today. Removing
 # a line is the unit of progress on #1349; adding one is not allowed.
 
-crates/fbuild-build-engine/src/build_info.rs
-crates/fbuild-build-engine/src/compile_database/tests/clang.rs
-crates/fbuild-build-engine/src/compile_database/tests/generate.rs
-crates/fbuild-build-engine/src/compiler_tests.rs
-crates/fbuild-build-engine/src/linker.rs
 crates/fbuild-build/src/compile_many.rs
 crates/fbuild-build/tests/avr_build.rs
 crates/fbuild-build/tests/clangd_check_parity.rs