diff --git a/vlib/compiler/cc.v b/vlib/compiler/cc.v
index 4885d38b5f..cd29930485 100644
--- a/vlib/compiler/cc.v
+++ b/vlib/compiler/cc.v
@@ -7,6 +7,7 @@ module compiler
 import (
 	os
 	time
+	filepath
 )
 
 fn todo() {
@@ -152,7 +153,7 @@ fn (v mut V) cc() {
 		a << '-c'
 	}
 	else if v.pref.is_cache {
-		builtin_o_path := os.join(v_modules_path, 'cache', 'vlib', 'builtin.o')
+		builtin_o_path := filepath.join(v_modules_path, 'cache', 'vlib', 'builtin.o')
 		a << builtin_o_path.replace('builtin.o', 'strconv.o') // TODO hack no idea why this is needed
 		if os.file_exists(builtin_o_path) {
 			libs = builtin_o_path
diff --git a/vlib/compiler/main.v b/vlib/compiler/main.v
index 906287195a..6506f4999c 100644
--- a/vlib/compiler/main.v
+++ b/vlib/compiler/main.v
@@ -7,6 +7,7 @@ module compiler
 import (
 	os
 	strings
+	filepath
 )
 
 pub const (
@@ -650,11 +651,11 @@ pub fn (v &V)  get_user_files() []string {
 	mut user_files := []string
 
 	if v.pref.is_test {
-		user_files << os.join(v.vroot,'vlib','compiler','preludes','tests_assertions.v')
+		user_files << filepath.join(v.vroot,'vlib','compiler','preludes','tests_assertions.v')
 	}
 	
 	if v.pref.is_test && v.pref.is_stats {
-		user_files << os.join(v.vroot,'vlib','compiler','preludes','tests_with_stats.v')
+		user_files << filepath.join(v.vroot,'vlib','compiler','preludes','tests_with_stats.v')
 	}
 	
 	// v volt/slack_test.v: compile all .v files to get the environment
diff --git a/vlib/filepath/filepath.v b/vlib/filepath/filepath.v
new file mode 100644
index 0000000000..016a84abf8
--- /dev/null
+++ b/vlib/filepath/filepath.v
@@ -0,0 +1,36 @@
+module filepath
+
+import(
+	os
+	strings
+)
+
+// return the extension in the file `path`
+pub fn ext(path string) string {
+	pos := path.last_index_byte(`.`)
+	if pos != -1 {
+		return path[pos..]
+	}
+	return ''
+}
+
+// returns true if `path` is absolute
+pub fn is_abs(path string) bool {
+	$if windows {
+		return path[0] == `/` || // incase we're in MingGW bash
+			(path[0].is_letter() && path[1] == `:`)
+	}
+	return path[0] == `/`
+}
+
+// pass directories as parameters, returns path as string 
+// TODO use []string.join once ...string becomes "[]string"
+pub fn join(base string, dirs ...string) string {
+	mut path := strings.new_builder(50)
+	path.write(base.trim_right('\\/'))
+	for d in dirs {
+		path.write(os.path_separator)
+		path.write(d)
+	}
+	return path.str()
+}
diff --git a/vlib/os/os.v b/vlib/os/os.v
index 683719d314..ee225125fc 100644
--- a/vlib/os/os.v
+++ b/vlib/os/os.v
@@ -4,7 +4,7 @@
 
 module os
 
-import strings
+import filepath
 
 #include <sys/stat.h>
 #include <signal.h>
@@ -920,13 +920,7 @@ pub fn mkdir_all(path string) {
 	}
 }
 
-// TODO use []string.join once ...string becomes "[]string"
 pub fn join(base string, dirs ...string) string {
-	mut path := strings.new_builder(50)
-	path.write(base.trim_right('\\/'))
-	for d in dirs {
-		path.write(os.path_separator)
-		path.write(d)
-	}
-	return path.str()
+	println('use filepath.join')
+	return filepath.join(base, dirs)
 }