diff --git a/src/fn_colors.cpp b/src/fn_colors.cpp
index f074528dc..43aa3f9ad 100644
--- a/src/fn_colors.cpp
+++ b/src/fn_colors.cpp
@@ -1,3 +1,4 @@
+#include "sass.hpp"
 #include <cctype>
 #include <iomanip>
 #include "ast.hpp"
diff --git a/src/fn_numbers.cpp b/src/fn_numbers.cpp
index e4bec9936..136226f1e 100644
--- a/src/fn_numbers.cpp
+++ b/src/fn_numbers.cpp
@@ -1,3 +1,5 @@
+#include "sass.hpp"
+
 #include <cstdint>
 #include <cstdlib>
 #include <cmath>
@@ -8,7 +10,6 @@
 #include <algorithm>
 
 #include "ast.hpp"
-#include "sass.hpp"
 #include "units.hpp"
 #include "fn_utils.hpp"
 #include "fn_numbers.hpp"
diff --git a/src/fn_strings.cpp b/src/fn_strings.cpp
index 1f33c343d..8b6ac0e96 100644
--- a/src/fn_strings.cpp
+++ b/src/fn_strings.cpp
@@ -1,7 +1,7 @@
+#include "sass.hpp"
 #include <cctype>
 #include "utf8.h"
 #include "ast.hpp"
-#include "sass.hpp"
 #include "fn_utils.hpp"
 #include "fn_strings.hpp"
 
diff --git a/src/listize.hpp b/src/listize.hpp
index 8fa148816..a0f6a96eb 100644
--- a/src/listize.hpp
+++ b/src/listize.hpp
@@ -1,6 +1,8 @@
 #ifndef SASS_LISTIZE_H
 #define SASS_LISTIZE_H
 
+#include "sass.hpp"
+
 #include <vector>
 #include <iostream>
 
diff --git a/src/parser.hpp b/src/parser.hpp
index 7ee515b75..536cbaa51 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -1,6 +1,8 @@
 #ifndef SASS_PARSER_H
 #define SASS_PARSER_H
 
+#include "sass.hpp"
+
 #include <string>
 #include <vector>