diff --git a/backend/common.c b/backend/common.c
index 5c62e94c..0e012fa3 100644
--- a/backend/common.c
+++ b/backend/common.c
@@ -46,14 +46,6 @@ int ctoi(const char source) {
     return (source - 'A' + 10);
 }
 
-/* Converts an integer value to its hexadecimal character */
-char itoc(const int source) {
-    if ((source >= 0) && (source <= 9)) {
-        return ('0' + source);
-    } else {
-        return ('A' + (source - 10));
-    }
-}
 
 /* Convert an integer value to a string representing its binary equivalent */
 void bin_append(const int arg, const int length, char *binary) {
@@ -74,6 +66,14 @@ void bin_append(const int arg, const int length, char *binary) {
     return;
 }
 
+/* Converts an integer value to its hexadecimal character */
+char itoc(const int source) {
+    if ((source >= 0) && (source <= 9)) {
+        return ('0' + source);
+    } else {
+        return ('A' + (source - 10));
+    }
+}
 /* Converts lower case characters to upper case in a string source[] */
 void to_upper(unsigned char source[]) {
     size_t i, src_len = ustrlen(source);
diff --git a/backend/common.h b/backend/common.h
index 73b87218..4bc3fc19 100644
--- a/backend/common.h
+++ b/backend/common.h
@@ -57,10 +57,10 @@ extern "C" {
     extern size_t ustrlen(const unsigned char source[]);
     extern int ctoi(const char source);
     extern char itoc(const int source);
-    extern void bin_append(const int arg, const int length, char *binary);
     extern void to_upper(unsigned char source[]);
     extern int is_sane(const char test_string[], const unsigned char source[], const size_t length);
     extern void lookup(const char set_string[], const char *table[], const char data, char dest[]);
+    extern void bin_append(const int arg, const int length, char *binary);
     extern int posn(const char set_string[], const char data);
     extern int module_is_set(const struct zint_symbol *symbol, const int y_coord, const int x_coord);
     extern void set_module(struct zint_symbol *symbol, const int y_coord, const int x_coord);
diff --git a/backend/composite.c b/backend/composite.c
index d69427a6..a5bd590c 100644
--- a/backend/composite.c
+++ b/backend/composite.c
@@ -51,6 +51,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <assert.h>
 #include <math.h>
 #include <assert.h>
 #ifdef _MSC_VER
diff --git a/backend/qr.c b/backend/qr.c
index cf0364a0..87defbca 100644
--- a/backend/qr.c
+++ b/backend/qr.c
@@ -1313,7 +1313,7 @@ static void applyOptimisation(const int version,char inputMode[], const size_t i
     free(blockMode);
 }
 
-static int blockLength(const size_t start,const char inputMode[],const size_t inputLength) {
+static size_t blockLength(const size_t start,const char inputMode[],const size_t inputLength) {
     /* Find the length of the block starting from 'start' */
     size_t i;
     int    count;