diff --git a/src/assert.cc b/src/assert.cc
index eb88120c..67dc6e07 100644
--- a/src/assert.cc
+++ b/src/assert.cc
@@ -2,6 +2,7 @@
 
 #include "exception.hh"
 #include "debug.hh"
+#include "backtrace.hh"
 
 #if defined(__CYGWIN__)
 #include <windows.h>
@@ -26,8 +27,10 @@ private:
 
 void on_assert_failed(const char* message)
 {
-    String debug_info = format("pid: {}", getpid());
-    write_debug(format("assert failed: '{}' ", message, debug_info));
+    char* callstack = Backtrace{}.desc();
+    String debug_info = format("pid: {}\ncallstack:\n{}", getpid(), callstack);
+    free(callstack);
+    write_debug(format("assert failed: '{}'\n{}", message, debug_info));
 
     const auto msg = format("{}\n[Debug Infos]\n{}", message, debug_info);
 #if defined(__CYGWIN__)
diff --git a/src/backtrace.cc b/src/backtrace.cc
index f7be9f76..4f8aacf8 100644
--- a/src/backtrace.cc
+++ b/src/backtrace.cc
@@ -21,7 +21,7 @@ Backtrace::Backtrace()
     #endif
 }
 
-const char* Backtrace::desc() const
+char* Backtrace::desc() const
 {
     #if defined(__linux__) || defined(__APPLE__)
     char** symbols = backtrace_symbols(stackframes, num_frames);
diff --git a/src/backtrace.hh b/src/backtrace.hh
index 5eca8827..8f146372 100644
--- a/src/backtrace.hh
+++ b/src/backtrace.hh
@@ -11,7 +11,7 @@ struct Backtrace
     int num_frames = 0;
 
     Backtrace();
-    const char* desc() const;
+    char* desc() const;
 };
 
 }