diff --git a/builtins.cpp b/builtins.cpp
index 992a1a6..729f925 100644
--- a/builtins.cpp
+++ b/builtins.cpp
@@ -12,6 +12,8 @@
 
 #include <cstdio>
 #include <cctype>
+#include <cstring>
+
 #include <unistd.h>
 
 #include "cxx/string_splitter.h"
diff --git a/environment.cpp b/environment.cpp
index 3c367fe..95bf3db 100644
--- a/environment.cpp
+++ b/environment.cpp
@@ -179,7 +179,7 @@ namespace {
 
 	void Environment::echo(const char *fmt, ...) const {
 		if (_echo && !_startup) {
-			for (unsigned i = 0; i <= _indent; ++i) {
+			for (int i = 0; i <= _indent; ++i) {
 				fputc(' ', stderr);
 				fputc(' ', stderr);
 			}