diff --git a/src/build.cpp b/src/build.cpp
index c1b425f..5f3d88f 100644
--- a/src/build.cpp
+++ b/src/build.cpp
@@ -5,9 +5,9 @@
 
 #include "fs.hpp"
 #include <sstream>
-#include <stddef.h>
+#include <cstddef>
 #include <stdexcept>
-#include <stdlib.h>
+#include <cstdlib>
 #include <system_error>
 
 namespace cmkr {
@@ -94,4 +94,4 @@ int cmkr_build_install(void) {
     } catch (...) {
         return cmkr::error::Status(cmkr::error::Status::Code::InstallError);
     }
-}
\ No newline at end of file
+}
diff --git a/src/error.cpp b/src/error.cpp
index a8d2552..1415bbe 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -1,6 +1,6 @@
 #include "error.hpp"
 
-#include <assert.h>
+#include <cassert>
 
 namespace cmkr {
 namespace error {
@@ -14,11 +14,12 @@ Status::Code Status::code() const noexcept { return ec_; }
 } // namespace error
 } // namespace cmkr
 
-const char *err_string[] = {
-    "Success", "Runtime error", "Initialization error", "CMake generation error", "Build error",
+// strings for cmkr::error::Status::Code
+static const char *err_string[] = {
+    "Success", "Runtime error", "Initialization error", "CMake generation error", "Build error", "Clean error", "Install error",
 };
 
 const char *cmkr_error_status(int i) {
-    assert(i >= 0 && i < 5);
+    assert(i >= 0 && i < (sizeof(err_string) / sizeof(*(err_string))));
     return err_string[i];
-}
\ No newline at end of file
+}