diff --git a/main.cpp b/main.cpp
index 7516085f..617f48d0 100644
--- a/main.cpp
+++ b/main.cpp
@@ -16,11 +16,16 @@
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simplecpp.h"
-
+#include <cstdlib>
+#include <cstring>
 #include <fstream>
 #include <iostream>
-#include <cstring>
+#include <map>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "simplecpp.h"
 
 int main(int argc, char **argv)
 {
diff --git a/simplecpp.cpp b/simplecpp.cpp
index 5444238c..68e91acd 100755
--- a/simplecpp.cpp
+++ b/simplecpp.cpp
@@ -24,6 +24,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <cctype>
 #include <climits>
 #include <cstddef>
 #include <cstdlib>
@@ -33,13 +34,17 @@
 #include <fstream> // IWYU pragma: keep
 #include <iostream>
 #include <limits>
+#include <list>
+#include <set>
 #include <sstream> // IWYU pragma: keep
 #include <stack>
 #include <stdexcept>
+#include <string>
 #if __cplusplus >= 201103L
 #include <unordered_map>
 #endif
 #include <utility>
+#include <vector>
 
 #ifdef SIMPLECPP_WINDOWS
 #include <windows.h>
diff --git a/test.cpp b/test.cpp
index 4d38db37..11e5989f 100644
--- a/test.cpp
+++ b/test.cpp
@@ -16,10 +16,17 @@
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <cctype>
+#include <cstdlib>
+#include <cstring>
+#include <exception>
 #include <iostream>
-#include <limits>
+#include <map>
 #include <sstream>
+#include <stdexcept>
+#include <string>
 #include <vector>
+
 #include "simplecpp.h"
 
 static int numberOfFailedAssertions = 0;