diff --git a/bacnet-stack/ports/pic18f6720/18F6720.lkr b/bacnet-stack/ports/pic18f6720/18F6720.lkr
index cba46077..a3922646 100644
--- a/bacnet-stack/ports/pic18f6720/18F6720.lkr
+++ b/bacnet-stack/ports/pic18f6720/18F6720.lkr
@@ -6,7 +6,7 @@ LIBPATH .
 
 FILES c018i.o
 FILES clib.lib
-FILES p18f6720.lib
+FILES p18F6720.lib
 
 CODEPAGE   NAME=vectors    START=0x0            END=0x29           PROTECTED
 CODEPAGE   NAME=page       START=0x2A           END=0x1FFFF
diff --git a/bacnet-stack/ports/pic18f6720/hardware.h b/bacnet-stack/ports/pic18f6720/hardware.h
index a048e830..2cb09788 100644
--- a/bacnet-stack/ports/pic18f6720/hardware.h
+++ b/bacnet-stack/ports/pic18f6720/hardware.h
@@ -25,7 +25,7 @@
 #ifndef HARDWARE_H
 #define HARDWARE_H
 
-#include <p18F6720.h>
+#include <p18f6720.h>
 #include <stdint.h>
 #include <stdbool.h>
 
diff --git a/bacnet-stack/ports/pic18f6720/isr.c b/bacnet-stack/ports/pic18f6720/isr.c
index e09b145c..503e5919 100644
--- a/bacnet-stack/ports/pic18f6720/isr.c
+++ b/bacnet-stack/ports/pic18f6720/isr.c
@@ -22,7 +22,7 @@
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 *********************************************************************/
-#include <p18F6720.h>
+#include <p18f6720.h>
 #include "stdint.h"
 #include "hardware.h"
 #include "rs485.h"
diff --git a/bacnet-stack/ports/pic18f6720/main.c b/bacnet-stack/ports/pic18f6720/main.c
index 31d1fdb4..79a007fc 100644
--- a/bacnet-stack/ports/pic18f6720/main.c
+++ b/bacnet-stack/ports/pic18f6720/main.c
@@ -26,7 +26,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>     /* for memmove */
-#include <p18F6720.h>
+#include <p18f6720.h>
 #include <stdlib.h>
 #include <string.h>
 #include "stdint.h"