diff --git a/headers/posix/langinfo.h b/headers/posix/langinfo.h
index cbd63bd8b2..d5dc7c819f 100644
--- a/headers/posix/langinfo.h
+++ b/headers/posix/langinfo.h
@@ -83,9 +83,9 @@ enum {
 	_NL_LANGINFO_LAST
 };
 
-// According to the POSIX base specs v7, the above need to be available as
-// symbolic constants, so we define them individually to their respective
-// enumeration name.
+/* According to the POSIX base specs v7, the above need to be available as
+   symbolic constants, so we define them individually to their respective
+   enumeration name. */
 #define CODESET CODESET
 #define D_T_FMT D_T_FMT
 #define D_FMT D_FMT
diff --git a/headers/posix/sys/select.h b/headers/posix/sys/select.h
index 064a0ddfb3..3f41e137ce 100644
--- a/headers/posix/sys/select.h
+++ b/headers/posix/sys/select.h
@@ -43,7 +43,7 @@ typedef struct fd_set {
 #define _FD_BITSINDEX(fd) ((fd) / NFDBITS)
 #define _FD_BIT(fd) (1L << ((fd) % NFDBITS))
 
-// FD_ZERO uses memset
+/* FD_ZERO uses memset */
 #include <string.h>
 
 #define FD_ZERO(set) memset((set), 0, sizeof(fd_set))