diff --git a/src/c/a3.c b/src/c/a3.c
index 7b55bbb..1af6471 100644
--- a/src/c/a3.c
+++ b/src/c/a3.c
@@ -36,16 +36,17 @@ void memdump(unsigned char *string) {
 
 int memreplace(char *string, char cin, char cout, char **caddr) {
     int found = 0;
+    char *bla = NULL;
     for (int i = 0; i < strlen(string); ++i) {
         if(string[i] == cin) {
             found++;
-            string[i] = cout;
+
             //TODO: fix pointer assignment
             //if(*caddr) free(caddr);
-            char *bla = &string[i];
-            caddr = &bla;
+            bla = &string[i];
 
         }
+        *caddr = bla;
     }
     return found;
 }
@@ -72,7 +73,7 @@ int main(int argc, char **argv) {
     strcpy((char *) copy, argv[1]);
 
     char **lastAddress = NULL;
-    int count = memreplace(argv[1], *argv[2], *argv[3], lastAddress);
+    int count = memreplace((char *) *copy, *argv[2], *argv[3], lastAddress);
     printf("Suchzeichen wurde %i mal gefunden und ersetzt\n", count);
     //TODO: change type
     printf("zuletzt an Addresse 0x%02x \n", (unsigned int) &lastAddress);