diff --git a/src/cw/cw_strdup.c b/src/cw/cw_strdup.c
index 2491d676..6a5169bd 100644
--- a/src/cw/cw_strdup.c
+++ b/src/cw/cw_strdup.c
@@ -1,15 +1,19 @@
 #include <string.h>
 #include <stdlib.h>
 
+#include "cw.h"
+
 /**
  * @brief Duplicate a string
  * @param s string to duplicate
  * @return duplicated string, the memory acllocated has to be freed by #free.
+ * if there was an error allocating the memory, the return value is NULL.
  */
-char *cw_strdup(const char *s) {
-    size_t size = strlen(s) + 1;
-    char *p = malloc(size);
-    if (p) 
-        memcpy(p, s, size);
-    return p;
+char *cw_strdup(const char *s)
+{
+	size_t size = strlen(s) + 1;
+	char *p = malloc(size);
+	if (p != NULL)
+		memcpy(p, s, size);
+	return p;
 }