diff --git a/lib/liblaunch/launch.c b/lib/liblaunch/launch.c
index 0463843..682e3e5 100644
--- a/lib/liblaunch/launch.c
+++ b/lib/liblaunch/launch.c
@@ -70,15 +70,14 @@ static virt_addr_t write_bootstrap_data(
 		bs->bs_argv = (const char **)remote_argv;
 	}
 
-	if (bs->bs_envc > 0) {
-		virt_addr_t remote_envp;
-		envp = stack_writer_put(
-			stack,
-			NULL,
-			bs->bs_envc * sizeof(char *),
-			&remote_envp);
-		bs->bs_envp = (const char **)remote_envp;
-	}
+	/* envc+1 so there is space for a null terminator */
+	virt_addr_t remote_envp;
+	envp = stack_writer_put(
+		stack,
+		NULL,
+		(bs->bs_envc + 1) * sizeof(char *),
+		&remote_envp);
+	bs->bs_envp = (const char **)remote_envp;
 
 	size_t i = 0, j = 0;
 	if (interpreter) {
@@ -95,11 +94,12 @@ static virt_addr_t write_bootstrap_data(
 		argv[i] = (const char *)arg_ptr;
 	}
 
-	for (size_t i = 0; i < bs->bs_envc; i++) {
-		virt_addr_t env_ptr;
+	virt_addr_t env_ptr;
+	for (i = 0; i < bs->bs_envc; i++) {
 		stack_writer_put_string(stack, params->p_envp[i], &env_ptr);
 		envp[i] = (const char *)env_ptr;
 	}
+	envp[i] = NULL;
 
 	return bs_remote;
 }