diff --git a/README.md b/README.md
index 646799b..51c0eab 100644
--- a/README.md
+++ b/README.md
@@ -187,4 +187,5 @@ Please refer to `examples/arduino/README.md` for more info about building and ru
         - `NMBS_SERVER_READ_WRITE_REGISTERS_DISABLED`
         - `NMBS_SERVER_READ_DEVICE_IDENTIFICATION_DISABLED`
     - `NMBS_STRERROR_DISABLED` to disable the code that converts `nmbs_error`s to strings
+    - `NMBS_BITFIELD_MAX` to set the size of the `nmbs_bitfield` type, used to store coil values (default is `2000`)
 - Debug prints about received and sent messages can be enabled by defining `NMBS_DEBUG`
diff --git a/nanomodbus.c b/nanomodbus.c
index 5786301..d00f212 100644
--- a/nanomodbus.c
+++ b/nanomodbus.c
@@ -546,7 +546,7 @@ static nmbs_error recv_read_discrete_res(nmbs_t* nmbs, nmbs_bitfield values) {
     uint8_t coils_bytes = get_1(nmbs);
     NMBS_DEBUG_PRINT("b %d\t", coils_bytes);
 
-    if (coils_bytes > NMBS_MAX_COIL_BYTES) {
+    if (coils_bytes > NMBS_BITFIELD_BYTES_MAX) {
         return NMBS_ERROR_INVALID_RESPONSE;
     }
 
@@ -1958,7 +1958,7 @@ nmbs_error nmbs_client_create(nmbs_t* nmbs, const nmbs_platform_conf* platform_c
 
 
 static nmbs_error read_discrete(nmbs_t* nmbs, uint8_t fc, uint16_t address, uint16_t quantity, nmbs_bitfield values) {
-    if (quantity < 1 || quantity > NMBS_MAX_COILS)
+    if (quantity < 1 || quantity > NMBS_BITFIELD_MAX)
         return NMBS_ERROR_INVALID_ARGUMENT;
 
     if ((uint32_t) address + (uint32_t) quantity > ((uint32_t) 0xFFFF) + 1)
diff --git a/nanomodbus.h b/nanomodbus.h
index a9ae15d..5d3d356 100644
--- a/nanomodbus.h
+++ b/nanomodbus.h
@@ -78,21 +78,21 @@ typedef enum nmbs_error {
  */
 #define nmbs_error_is_exception(e) ((e) > 0 && (e) < 5)
 
-#ifndef NMBS_MAX_COILS
- #define NMBS_MAX_COILS 2000
+#ifndef NMBS_BITFIELD_MAX
+#define NMBS_BITFIELD_MAX 2000
 #endif
 
 /* check coil count divisible by 8 */
-#if ((NMBS_MAX_COILS & 7) > 0)
- #error "NMBS_MAX_COILS must be disible by 8"
+#if ((NMBS_BITFIELD_MAX & 7) > 0)
+#error "NMBS_BITFIELD_MAX must be divisible by 8"
 #endif
 
-#define NMBS_MAX_COIL_BYTES (NMBS_MAX_COILS / 8)
+#define NMBS_BITFIELD_BYTES_MAX (NMBS_BITFIELD_MAX / 8)
 
 /**
  * Bitfield consisting of 2000 coils/discrete inputs
  */
-typedef uint8_t nmbs_bitfield[NMBS_MAX_COIL_BYTES];
+typedef uint8_t nmbs_bitfield[NMBS_BITFIELD_BYTES_MAX];
 
 /**
  * Bitfield consisting of 256 values