diff --git a/macro.go b/macro.go
index b27e441..10911d4 100644
--- a/macro.go
+++ b/macro.go
@@ -21,8 +21,6 @@ import (
 	"strings"
 )
 
-type macro []string
-
 type macroDef struct {
 	Prefix []string
 	Suffix []string
diff --git a/task.go b/task.go
index 18c5c71..077ac3e 100644
--- a/task.go
+++ b/task.go
@@ -22,15 +22,23 @@
 
 package main
 
-import "fmt"
+import (
+	"fmt"
+	"os"
+	"strings"
+)
 
 type taskDef struct {
 	Deps   []string
 	Links  []link
 	Cmds   []command
 	Macros []macro
+	Envs   []env
 }
 
+type macro []string
+type env []string
+
 func (t *taskDef) process(taskName, srcDir, dstDir string, conf *config, flags int) error {
 	handled, ok := conf.tasksHandled[taskName]
 	if ok && handled {
@@ -50,14 +58,27 @@ func (t *taskDef) process(taskName, srcDir, dstDir string, conf *config, flags i
 		}
 	}
 
+	for _, envItems := range t.Envs {
+		switch {
+		case len(envItems) == 0:
+			continue
+		case len(envItems) == 1:
+			os.Unsetenv(envItems[0])
+		case len(envItems) == 2:
+			os.Setenv(envItems[0], envItems[1])
+		default:
+			os.Setenv(envItems[0], strings.Join(envItems[1:], ","))
+		}
+	}
+
 	if flags&flagNoMacro == 0 {
-		for _, macro := range t.Macros {
-			if len(macro) == 0 {
+		for _, macroItems := range t.Macros {
+			if len(macroItems) == 0 {
 				continue
 			}
 
-			macroName := macro[0]
-			macroParams := macro[1:]
+			macroName := macroItems[0]
+			macroParams := macroItems[1:]
 
 			depMacro, ok := conf.Macros[macroName]
 			if !ok {