diff --git a/pTk/config/Hstrdup.c b/pTk/config/Hstrdup.c
index bbde6d2c..4c6b6abf 100644
--- a/pTk/config/Hstrdup.c
+++ b/pTk/config/Hstrdup.c
@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include <string.h>
 
 #define STRING "Whatever"
diff --git a/pTk/config/Hstrtoul.c b/pTk/config/Hstrtoul.c
index a5be7031..e29e4e4e 100644
--- a/pTk/config/Hstrtoul.c
+++ b/pTk/config/Hstrtoul.c
@@ -1,4 +1,5 @@
 #include <stdlib.h>
+#include <string.h>
 
 int main()
 {char *e;