diff --git a/libs/libc/include/stdlib.h b/libs/libc/include/stdlib.h
index 1909b7e6..37018749 100644
--- a/libs/libc/include/stdlib.h
+++ b/libs/libc/include/stdlib.h
@@ -31,7 +31,7 @@ extern "C"
     long long atoll(const char* str);
 
     /* Returns an integer (of type unsigned long) parsed from the string str. */
-    unsigned long strtoul(const char* str, const char** endptr, int base);
+    unsigned long strtoul(const char* str, char** endptr, int base);
 
     /* Not implemented. */
     char* getenv(const char*);
diff --git a/libs/libc/src/stdlib.cpp b/libs/libc/src/stdlib.cpp
index 941a73c0..9bb532cc 100644
--- a/libs/libc/src/stdlib.cpp
+++ b/libs/libc/src/stdlib.cpp
@@ -46,7 +46,7 @@ extern "C"
         return string_to_integer_type<long long>(str);
     }
 
-    unsigned long strtoul(const char* str, const char** endptr, int base)
+    unsigned long strtoul(const char* str, char** endptr, int base)
     {
         if (base != 0 && base != 10) NOT_IMPLEMENTED("strtoul with base not in (0,10)");
         if (endptr) NOT_IMPLEMENTED("strtoul with non-null endptr");