diff --git a/src/alias.c b/src/alias.c
index fb292c5..b334ceb 100644
--- a/src/alias.c
+++ b/src/alias.c
@@ -12,6 +12,7 @@
 #include <unistd.h>
 
 #include "alias.h"
+#include "common.h"
 #include "history.h"
 #include "utils.h"
 
@@ -69,6 +70,7 @@ char *get_alias(char *buffer, int i, alias_t *alias)
     return buffer;
 }
 
+static
 bool replace_alias(char **buffer, alias_t *alias)
 {
     char *tmp_buff = *buffer;
@@ -78,12 +80,24 @@ bool replace_alias(char **buffer, alias_t *alias)
         tmp_buff = get_alias(tmp_buff, i, alias);
         if (tmp_buff == NULL)
             return false;
+        if (strncmp(*buffer, tmp_buff, strlen(*buffer)) == 0)
+            return false;
         i = skip_to_next_token(tmp_buff, i);
     }
     *buffer = tmp_buff;
     return true;
 }
 
+int parse_alias(char **buffer, alias_t *alias)
+{
+    size_t i = 0;
+
+    for (; i < 1000 && replace_alias(buffer, alias); i++);
+    if (i > 900)
+        return fprintf(stderr, "Alias loop.\n"), RETURN_FAILURE;
+    return RETURN_SUCCESS;
+}
+
 alias_t init_alias(void)
 {
     alias_t alias;
diff --git a/src/alias.h b/src/alias.h
index 997f6f1..6a939da 100644
--- a/src/alias.h
+++ b/src/alias.h
@@ -16,6 +16,6 @@ typedef struct alias_s {
 } alias_t;
 
 void free_alias(alias_t *alias);
-bool replace_alias(char **buffer, alias_t *alias);
+int parse_alias(char **buffer, alias_t *alias);
 alias_t init_alias(void);
 #endif /* ALIAS*/
diff --git a/src/builtins/where.c b/src/builtins/where.c
index 1cffa75..5e8a8a5 100644
--- a/src/builtins/where.c
+++ b/src/builtins/where.c
@@ -68,7 +68,7 @@ bool search_cmd(ef_t *ef, char *arg)
 
     if (!alias_path.str)
         return false;
-    replace_alias(&alias_path.str, ef->exec_ctx->alias);
+    parse_alias(&alias_path.str, ef->exec_ctx->alias);
     if (strcmp(arg, alias_path.str) != 0)
         dprintf(ef->out_fd, "%s is aliased to %s\n", arg, alias_path.str);
     search_builtins(ef, arg);
diff --git a/src/builtins/which.c b/src/builtins/which.c
index 264e8e6..e332df5 100644
--- a/src/builtins/which.c
+++ b/src/builtins/which.c
@@ -54,7 +54,7 @@ bool search_cmd(ef_t *ef, char *arg)
         return false;
     if (bin_path == NULL)
         return free(alias_path.str), NULL;
-    replace_alias(&alias_path.str, ef->exec_ctx->alias);
+    parse_alias(&alias_path.str, ef->exec_ctx->alias);
     if (strcmp(arg, alias_path.str) != 0)
         return dprintf(ef->out_fd, "%s:\t aliased to %s\n", arg,
             alias_path.str), true;
diff --git a/src/update_command.c b/src/update_command.c
index 4a4205a..591cb68 100644
--- a/src/update_command.c
+++ b/src/update_command.c
@@ -53,7 +53,10 @@ size_t update_command(char **buffer,
     if (parse_history(buffer, &buffer_len,
         buffer_sz, &exec_ctx->history_command) == 84)
         return RETURN_SUCCESS;
-    replace_alias(buffer, exec_ctx->alias);
+    if (parse_alias(buffer, exec_ctx->alias) == RETURN_FAILURE) {
+        exec_ctx->history->last_exit_code = RETURN_FAILURE;
+        return 0;
+    }
     exec_ctx->history_command = save_command(*buffer,
         exec_ctx->history_command);
     return buffer_len;
diff --git a/validation_tests.py b/validation_tests.py
index 6d45ed3..90274f8 100644
--- a/validation_tests.py
+++ b/validation_tests.py
@@ -180,6 +180,7 @@ TESTS = [
         cmds=[
             "ll\nalias ll ls\nll\n",
             "alias ls ls\nls\nalias\n",
+            "alias a b\nalias b a\na\n",
             "ll\n",
         ],
         depends_on=()