diff --git a/git.go b/git.go
index b6a2655..19d70a3 100644
--- a/git.go
+++ b/git.go
@@ -2,8 +2,10 @@ package tagpr
 
 import (
 	"bytes"
+	"fmt"
 	"io"
 	"log"
+	"os"
 	"os/exec"
 	"strings"
 )
@@ -20,7 +22,7 @@ func (c *commander) getGitPath() string {
 	return c.gitPath
 }
 
-func (c *commander) Cmd(prog string, args ...string) (string, string, error) {
+func (c *commander) Cmd(prog string, args []string, env map[string]string) (string, string, error) {
 	log.Println(prog, args)
 
 	var (
@@ -28,6 +30,12 @@ func (c *commander) Cmd(prog string, args ...string) (string, string, error) {
 		errBuf bytes.Buffer
 	)
 	cmd := exec.Command(prog, args...)
+	if env != nil {
+		cmd.Env = os.Environ()
+		for k, v := range env {
+			cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", k, v))
+		}
+	}
 	cmd.Stdout = io.MultiWriter(&outBuf, c.outStream)
 	cmd.Stderr = io.MultiWriter(&errBuf, c.errStream)
 	if c.dir != "" {
@@ -38,5 +46,5 @@ func (c *commander) Cmd(prog string, args ...string) (string, string, error) {
 }
 
 func (c *commander) Git(args ...string) (string, string, error) {
-	return c.Cmd(c.getGitPath(), args...)
+	return c.Cmd(c.getGitPath(), args, nil)
 }
diff --git a/tagpr.go b/tagpr.go
index 7c096c1..46bde44 100644
--- a/tagpr.go
+++ b/tagpr.go
@@ -312,7 +312,10 @@ OUT:
 			progArgs = []string{"-c", prog}
 			prog = "sh"
 		}
-		tp.c.Cmd(prog, progArgs...)
+		tp.c.Cmd(prog, progArgs, map[string]string{
+			"TAGPR_CURRENT_VERSION": currVer.Tag(),
+			"TAGPR_NEXT_VERSION":    nextVer.Tag(),
+		})
 	}
 
 	if len(vfiles) > 0 && vfiles[0] != "" {