diff --git a/Makefile b/Makefile
index c7a604c..5ce972a 100644
--- a/Makefile
+++ b/Makefile
@@ -16,7 +16,6 @@ CONFIGMKS = \
 
 MODULES_SRC = \
 	src/atoms.c \
-	src/constraints.c \
 	src/drw.c \
 	src/dwm.c \
 	src/geom.c \
@@ -43,7 +42,7 @@ TEST_SRC = \
 
 MAIN_SRC = $(MODULES_SRC) src/main.c
 
-MODULES_HDR = $(MODULES_SRC:.c=.h)
+MODULES_HDR = $(MODULES_SRC:.c=.h) src/constraints.h
 DWM_HDR     = $(DWM_SRC:.c=.h)
 MAIN_HDR    = $(MODULES_HDR) src/main.h
 
diff --git a/src/constraints.c b/src/constraints.c
deleted file mode 100644
index bfcd615..0000000
--- a/src/constraints.c
+++ /dev/null
@@ -1,16 +0,0 @@
-#include "constraints.h"
-
-#define MIN_MASTER_AREA_FACTOR 0.05
-#define MAX_MASTER_AREA_FACTOR 0.95
-
-float constraints_default_master_area_factor(const float default_master_area_factor)
-{
-	return constraints_master_area_factor(default_master_area_factor);
-}
-
-float constraints_master_area_factor(const float master_area_factor)
-{
-	if (master_area_factor < MIN_MASTER_AREA_FACTOR) return MIN_MASTER_AREA_FACTOR;
-	if (master_area_factor > MAX_MASTER_AREA_FACTOR) return MAX_MASTER_AREA_FACTOR;
-	return master_area_factor;
-}
diff --git a/src/constraints.rs b/src/constraints.rs
index c8602ef..2debba9 100644
--- a/src/constraints.rs
+++ b/src/constraints.rs
@@ -6,6 +6,8 @@ const MIN_DEFAULT_CLIENTS_IN_MASTER: c_int = 1;
 const MAX_DEFAULT_CLIENTS_IN_MASTER: c_int = 10000;
 const MIN_GAP_SIZE: c_int = 0;
 const MAX_GAP_SIZE: c_int = 10000;
+const MIN_MASTER_AREA_FACTOR: c_float = 0.05;
+const MAX_MASTER_AREA_FACTOR: c_float = 0.95;
 const MIN_MAX_CLIENTS_IN_MASTER: c_int = 1;
 const MAX_MAX_CLIENTS_IN_MASTER: c_int = 10000;
 const MIN_SNAP_DISTANCE: c_uint = 1;
@@ -27,12 +29,22 @@ pub fn default_clients_in_master(default_clients_in_master: c_int) -> c_int {
 	default_clients_in_master
 }
 
+pub fn default_master_area_factor(default_master_area_factor: c_float) -> c_float {
+	master_area_factor(default_master_area_factor)
+}
+
 pub fn gap_size(gap_size: c_int) -> c_int {
 	if gap_size < MIN_GAP_SIZE { return MIN_GAP_SIZE }
 	if gap_size > MAX_GAP_SIZE { return MAX_GAP_SIZE }
 	gap_size
 }
 
+pub fn master_area_factor(master_area_factor: c_float) -> c_float {
+	if master_area_factor < MIN_MASTER_AREA_FACTOR { return MIN_MASTER_AREA_FACTOR }
+	if master_area_factor > MAX_MASTER_AREA_FACTOR { return MAX_MASTER_AREA_FACTOR }
+	master_area_factor
+}
+
 pub fn max_clients_in_master(max_clients_in_master: c_int) -> c_int {
 	if max_clients_in_master < MIN_MAX_CLIENTS_IN_MASTER {
 		return MIN_MAX_CLIENTS_IN_MASTER
diff --git a/src/lib.rs b/src/lib.rs
index 58546ca..2d23a73 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,11 +12,21 @@ extern "C" fn constraints_default_clients_in_master(default_clients_in_master: c
 	constraints::default_clients_in_master(default_clients_in_master)
 }
 
+#[no_mangle]
+extern "C" fn constraints_default_master_area_factor(default_master_area_factor: c_float) -> c_float {
+	constraints::default_master_area_factor(default_master_area_factor)
+}
+
 #[no_mangle]
 extern "C" fn constraints_gap_size(gap_size: c_int) -> c_int {
 	constraints::gap_size(gap_size)
 }
 
+#[no_mangle]
+extern "C" fn constraints_master_area_factor(master_area_factor: c_float) -> c_float {
+	constraints::master_area_factor(master_area_factor)
+}
+
 #[no_mangle]
 extern "C" fn constraints_max_clients_in_master(max_clients_in_master: c_int) -> c_int {
 	constraints::max_clients_in_master(max_clients_in_master)