diff --git a/src/julec/compile.jule b/src/julec/compile.jule
index 1afb4a1a5..e9d8fb89b 100644
--- a/src/julec/compile.jule
+++ b/src/julec/compile.jule
@@ -202,10 +202,6 @@ fn gen_compile_cmd(source_path: str, &ir: &IR): (str, str) {
 }
 
 fn get_compile_path(): str {
-    // let mut path = join(PATH_WD, OUT_DIR)
-    // path = join(path, OUT_NAME)
-    // ret path
-
     // Return command-line argument form
     // instead of absolute path.
     ret join(OUT_DIR, OUT_NAME)
diff --git a/std/jule/build/env.jule b/std/jule/build/env.jule
index 4358bb62d..f60370f36 100644
--- a/std/jule/build/env.jule
+++ b/std/jule/build/env.jule
@@ -27,24 +27,14 @@ fn init() {
         panic("std::jule::build: executable file cannot found")
     }
 
-    let pwd = env::working_dir() else {
-        panic("std::jule::build: working directory path cannot found")
-        ret // To avoid assignment error.
-    }
-
-    let path_exec = path::dir(path)
-
-    // Go to parent directory.
-    path = path::join(path_exec, "..")
-
     // Break immutability to assign paths.
     unsafe {
-        *(&PATH_WD) = pwd
-        *(&PATH_EXEC) = path_exec
-        *(&PATH_STDLIB) = path::join(path, STDLIB)
-
-        *(&PATH_API) = path::join(PATH_EXEC, "..")
-        *(&PATH_API) = path::join(PATH_API, "api")
-        *(&PATH_API) = path::join(PATH_API, "jule.hpp")
+        *(&PATH_WD) = env::working_dir() else {
+            panic("std::jule::build: working directory path cannot found")
+            ret // To avoid assignment error.
+        }
+        *(&PATH_EXEC) = path::dir(path)
+        *(&PATH_STDLIB) = path::join(PATH_EXEC, "..", STDLIB)
+        *(&PATH_API) = path::join(PATH_EXEC, "..", "api", "jule.hpp")
     }
 }
\ No newline at end of file
diff --git a/std/strings/strings.jule b/std/strings/strings.jule
index 550f1d054..33f2997a6 100644
--- a/std/strings/strings.jule
+++ b/std/strings/strings.jule
@@ -455,12 +455,15 @@ pub fn trim(s: str, cutset: str): str {
 // Concatenates the parts of its first argument to create a single string.
 // The separator sep is placed between parts in the resulting string.
 pub fn join(parts: []str, sep: str): str {
-    if parts.len == 0 {
+    match parts.len {
+    | 0:
         ret ""
+    | 1:
+        ret parts[1]
     }
     let mut n = 0
     if sep.len > 0 {
-        if sep.len >= int.MAX/parts.len-1 {
+        if sep.len >= int.MAX/(parts.len-1) {
             panic("std::strings: join: output length overflow")
         }
         n += sep.len * (parts.len - 1)