diff --git a/arch/generic.h b/arch/generic.h
index 96f6478..3369616 100644
--- a/arch/generic.h
+++ b/arch/generic.h
@@ -17,6 +17,15 @@ void *memset(void* s, int c, unsigned long n) {
 }
 #endif // !MEMSET_DEFINED
 
+#ifndef _STRLEN_DEFINED
+#define _STRLEN_DEFINED
+int strlen(char* s) {
+  int len = 0;
+  for(;s[len] != 0; ++len);
+  return len;
+}
+#endif // !_STRLEN_DEFINED
+
 #ifndef _START_DEFINED
 #define _START_DEFINED
 // Generic _start implementation. Can't access any args
diff --git a/sys.h b/sys.h
index af6e18d..791acbf 100644
--- a/sys.h
+++ b/sys.h
@@ -143,5 +143,6 @@ int clock_nanosleep(clockid_t clockid, int flags, const struct timespec *t, stru
 uint32_t fork();
 
 void *memset(void* s, int c, unsigned long n);
+int strlen(char* s);
 
 #endif // !MINIMALSYS_H