diff --git a/src/bin/fish.rs b/src/bin/fish.rs
index 0b613f11c..a66ca9950 100644
--- a/src/bin/fish.rs
+++ b/src/bin/fish.rs
@@ -72,34 +72,11 @@ use std::path::{Path, PathBuf};
 use std::sync::atomic::Ordering;
 use std::sync::Arc;
 
-// FIXME: the following should just use env!(), this is to make `cargo test` work without CMake for now
-const DOC_DIR: &str = {
-    match option_env!("DOCDIR") {
-        Some(e) => e,
-        None => "(unused)",
-    }
-};
-const DATA_DIR: &str = {
-    match option_env!("DATADIR") {
-        Some(e) => e,
-        None => "(unused)",
-    }
-};
-const SYSCONF_DIR: &str = {
-    match option_env!("SYSCONFDIR") {
-        Some(e) => e,
-        None => "(unused)",
-    }
-};
-const BIN_DIR: &str = {
-    match option_env!("BINDIR") {
-        Some(e) => e,
-        None => "(unused)",
-    }
-};
+const DOC_DIR: &str = env!("DOCDIR");
+const DATA_DIR: &str = env!("DATADIR");
+const SYSCONF_DIR: &str = env!("SYSCONFDIR");
+const BIN_DIR: &str = env!("BINDIR");
 
-// C++ had this as optional, and used CMAKE_BINARY_DIR,
-// should probably be swapped to `OUT_DIR` once CMake is gone?
 const OUT_DIR: &str = env!("FISH_BUILD_DIR");
 
 /// container to hold the options specified within the command line
diff --git a/src/path.rs b/src/path.rs
index 6b2cc6f26..e28bb813b 100644
--- a/src/path.rs
+++ b/src/path.rs
@@ -184,8 +184,7 @@ pub fn path_get_path(cmd: &wstr, vars: &dyn Environment) -> Option<WString> {
 // PREFIX is defined at build time.
 pub static DEFAULT_PATH: Lazy<[WString; 3]> = Lazy::new(|| {
     [
-        // TODO This should use env!. The fallback is only to appease "cargo test" for now.
-        WString::from_str(option_env!("PREFIX").unwrap_or("/usr/local")) + L!("/bin"),
+        WString::from_str(env!("PREFIX")) + L!("/bin"),
         L!("/usr/bin").to_owned(),
         L!("/bin").to_owned(),
     ]
diff --git a/src/wutil/gettext.rs b/src/wutil/gettext.rs
index c4716a89d..b537ee42f 100644
--- a/src/wutil/gettext.rs
+++ b/src/wutil/gettext.rs
@@ -48,7 +48,7 @@ use internal::*;
 // Really init wgettext.
 fn wgettext_really_init() {
     let package_name = CString::new(PACKAGE_NAME).unwrap();
-    let localedir = CString::new(option_env!("LOCALEDIR").unwrap_or("UNDEFINED")).unwrap();
+    let localedir = CString::new(env!("LOCALEDIR")).unwrap();
     fish_bindtextdomain(&package_name, &localedir);
     fish_textdomain(&package_name);
 }