diff --git a/qoi.h b/qoi.h
index b733bb21..fdb32766 100644
--- a/qoi.h
+++ b/qoi.h
@@ -358,14 +358,14 @@ typedef union {
 
 static const unsigned char qoi_padding[8] = {0,0,0,0,0,0,0,1};
 
-void qoi_write_32(unsigned char *bytes, int *p, unsigned int v) {
+static void qoi_write_32(unsigned char *bytes, int *p, unsigned int v) {
 	bytes[(*p)++] = (0xff000000 & v) >> 24;
 	bytes[(*p)++] = (0x00ff0000 & v) >> 16;
 	bytes[(*p)++] = (0x0000ff00 & v) >> 8;
 	bytes[(*p)++] = (0x000000ff & v);
 }
 
-unsigned int qoi_read_32(const unsigned char *bytes, int *p) {
+static unsigned int qoi_read_32(const unsigned char *bytes, int *p) {
 	unsigned int a = bytes[(*p)++];
 	unsigned int b = bytes[(*p)++];
 	unsigned int c = bytes[(*p)++];