diff --git a/src/runtime/c/gu/seq.c b/src/runtime/c/gu/seq.c
index 5f0171977..54c92f4de 100644
--- a/src/runtime/c/gu/seq.c
+++ b/src/runtime/c/gu/seq.c
@@ -4,6 +4,7 @@
 #include <gu/str.h>
 #include <gu/assert.h>
 #include <stdlib.h>
+#include <malloc.h>
 
 struct GuSeq {
 	size_t len;
diff --git a/src/runtime/c/gu/string.c b/src/runtime/c/gu/string.c
index 8c9afd6e7..9a1677745 100644
--- a/src/runtime/c/gu/string.c
+++ b/src/runtime/c/gu/string.c
@@ -6,6 +6,7 @@
 #include <gu/utf8.h>
 #include <gu/assert.h>
 #include <stdlib.h>
+#include <malloc.h>
 
 struct GuStringBuf {
 	GuBuf* buf;
diff --git a/src/runtime/c/pgf/reader.c b/src/runtime/c/pgf/reader.c
index 68c620fb3..8163f16ed 100644
--- a/src/runtime/c/pgf/reader.c
+++ b/src/runtime/c/pgf/reader.c
@@ -14,6 +14,7 @@
 #include <gu/utf8.h>
 #include <math.h>
 #include <stdlib.h>
+#include <malloc.h>
 
 //
 // PgfReader