diff --git a/components/newlib/Kconfig b/components/newlib/Kconfig
index 9a30784c21..b1ba0ed516 100644
--- a/components/newlib/Kconfig
+++ b/components/newlib/Kconfig
@@ -160,6 +160,22 @@ menu "LibC"
                 - str[n]cpy
                 - str[n]cmp
 
+    config LIBC_ASSERT_BUFFER_SIZE
+        int "Assert message buffer size"
+        range 100 2048
+        default 200
+        help
+            Size of the buffer used to format assert failure messages.
+
+            When assertions fail, the system formats a message containing the function name,
+            file name, line number, and the failed expression. This option controls the
+            maximum length of this message.
+
+            If you encounter truncated assert messages (especially with C++ templates or
+            long function names), increase this value. The default value of 200 bytes
+            should be sufficient for most cases, but complex template expressions may
+            require larger buffers.
+
 endmenu # LibC
 
 config STDATOMIC_S32C1I_SPIRAM_WORKAROUND
diff --git a/components/newlib/src/assert.c b/components/newlib/src/assert.c
index 9bdb2f66cc..fbe3540d8e 100644
--- a/components/newlib/src/assert.c
+++ b/components/newlib/src/assert.c
@@ -9,6 +9,7 @@
 #include "esp_system.h"
 #include "soc/soc_memory_layout.h"
 #include "esp_private/cache_utils.h"
+#include "sdkconfig.h"
 
 #define ASSERT_STR              "assert failed: "
 #define CACHE_DISABLED_STR      "<cached disabled>"
@@ -39,7 +40,7 @@ void __attribute__((noreturn)) __assert_func(const char *file, int line, const c
     esp_system_abort(buff);
 #else
     char addr[11] = { 0 };
-    char buff[200];
+    char buff[CONFIG_LIBC_ASSERT_BUFFER_SIZE];
     char lbuf[5];
     uint32_t rem_len = sizeof(buff) - 1;
     uint32_t off = 0;