diff --git a/lib/posix/getenv.c b/lib/posix/getenv.c
index 9130f76d..881c05ec 100644
--- a/lib/posix/getenv.c
+++ b/lib/posix/getenv.c
@@ -22,7 +22,7 @@
 #include <string.h>
 #include <stdlib.h>
 
-// CONSTANT M2_PTR_SIZE 4
+// CONSTANT M2_PTR_SIZE 8
 #define M2_PTR_SIZE 1
 
 char *
diff --git a/lib/posix/setenv.c b/lib/posix/setenv.c
index 321a5ab1..c1f9849b 100644
--- a/lib/posix/setenv.c
+++ b/lib/posix/setenv.c
@@ -22,7 +22,7 @@
 #include <string.h>
 #include <stdlib.h>
 
-// CONSTANT M2_PTR_SIZE 4
+// CONSTANT M2_PTR_SIZE 8
 #define M2_PTR_SIZE 1
 
 int