diff --git a/cmd/exec.go b/cmd/exec.go
index d4e7b696..da388bd6 100644
--- a/cmd/exec.go
+++ b/cmd/exec.go
@@ -63,6 +63,7 @@ func execRun(cmd *cobra.Command, args []string) error {
 		}
 		for _, secret := range secrets {
 			envVarKey := strings.ToUpper(key(secret.Meta.Key))
+			envVarKey = strings.Replace(envVarKey, "-", "_", -1)
 
 			if env.IsSet(envVarKey) {
 				fmt.Fprintf(os.Stderr, "warning: overwriting environment variable %s\n", envVarKey)