diff --git a/src/asa241.c b/src/asa241.c
index 4992f44..2abc5be 100644
--- a/src/asa241.c
+++ b/src/asa241.c
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 # include <stdlib.h>
 # include <stdio.h>
 # include <math.h>
diff --git a/src/asa241.h b/src/asa241.h
index 3a4efe5..4b26fae 100644
--- a/src/asa241.h
+++ b/src/asa241.h
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 void normal_01_cdf_values ( int *n_data, double *x, double *fx );
 float r4_huge ( );
 float r4_normal_01_cdf_inverse ( float p );
diff --git a/src/black_scholes.c b/src/black_scholes.c
index cd56c40..39dc955 100644
--- a/src/black_scholes.c
+++ b/src/black_scholes.c
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #define _XOPEN_SOURCE
 
 #include "black_scholes.h"
diff --git a/src/black_scholes.h b/src/black_scholes.h
index 57cfdf7..e58cb78 100644
--- a/src/black_scholes.h
+++ b/src/black_scholes.h
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #ifndef BLACK_SCHOLES_H_
 #define BLACK_SCHOLES_H_
 
diff --git a/src/gbm_mc.c b/src/gbm_mc.c
index 5b87530..3f5536a 100644
--- a/src/gbm_mc.c
+++ b/src/gbm_mc.c
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #define _XOPEN_SOURCE
 #define max(X, Y) (((X) > (Y)) ? (X) : (Y))
 
diff --git a/src/gbm_mc.h b/src/gbm_mc.h
index 99ed8d8..88b4e07 100644
--- a/src/gbm_mc.h
+++ b/src/gbm_mc.h
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #ifndef GBM_MC
 #define GBM_MC
 
diff --git a/src/opt-pricer.c b/src/opt-pricer.c
index a660b43..2ad95bd 100644
--- a/src/opt-pricer.c
+++ b/src/opt-pricer.c
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #define _XOPEN_SOURCE
 
 #include "black_scholes.h"
diff --git a/src/sobol.cpp b/src/sobol.cpp
index 8ff423c..68d9176 100644
--- a/src/sobol.cpp
+++ b/src/sobol.cpp
@@ -1,3 +1,5 @@
+/* vim:filetype=cpp
+ */
 #include <cstdlib>
 #include <iostream>
 #include <fstream>
diff --git a/src/sobol.h b/src/sobol.h
index d160daa..163ea03 100644
--- a/src/sobol.h
+++ b/src/sobol.h
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #include <stdint.h>
 
 #ifdef __cplusplus
diff --git a/src/strptime.c b/src/strptime.c
index cc7a887..341b85f 100644
--- a/src/strptime.c
+++ b/src/strptime.c
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 /*	$Id$	*/
 /*	$NetBSD: strptime.c,v 1.18 1999/04/29 02:58:30 tv Exp $	*/
 
diff --git a/src/strptime.h b/src/strptime.h
index cc52de9..cce1043 100644
--- a/src/strptime.h
+++ b/src/strptime.h
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #ifndef STRPTIME_H
 #define STRPTIME_H
 
diff --git a/src/utils.c b/src/utils.c
index e226d43..3371b20 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #include <math.h>
 #include <stdlib.h>
 #include <time.h>
diff --git a/src/utils.h b/src/utils.h
index 74e294d..a8ebbb4 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -1,3 +1,5 @@
+/* vim:filetype=c
+ */
 #ifndef UTILS_H
 #define UTILS_H