diff --git a/auto/clang b/auto/clang
index 27fe03b5a..95a60823f 100644
--- a/auto/clang
+++ b/auto/clang
@@ -172,6 +172,20 @@ njs_feature_test="__attribute__((no_sanitize(\"undefined\"))) int main(void) {
 . auto/feature
 
 
+njs_feature="GCC __attribute__ nonstring"
+njs_feature_name=NJS_HAVE_GCC_ATTRIBUTE_NONSTRING
+njs_feature_run=no
+njs_feature_incs=
+njs_feature_libs=
+njs_feature_test="int main(void) {
+                      static const char str[3] __attribute__((nonstring)) =
+                          \"ABC\";
+
+                      return !!str[0];
+                  }"
+. auto/feature
+
+
 njs_feature="Address sanitizer"
 njs_feature_name=NJS_HAVE_ADDRESS_SANITIZER
 njs_feature_run=no
diff --git a/external/qjs_query_string_module.c b/external/qjs_query_string_module.c
index bb7872292..1d8c637f4 100644
--- a/external/qjs_query_string_module.c
+++ b/external/qjs_query_string_module.c
@@ -537,7 +537,7 @@ qjs_string_encode(const uint32_t *escape, size_t size, const u_char *src,
     u_char *dst)
 {
     uint8_t              byte;
-    static const u_char  hex[16] = "0123456789ABCDEF";
+    static const u_char  hex[16] NJS_NONSTRING = "0123456789ABCDEF";
 
     do {
         byte = *src++;
diff --git a/src/njs_clang.h b/src/njs_clang.h
index 2bd45a74f..da299a588 100644
--- a/src/njs_clang.h
+++ b/src/njs_clang.h
@@ -162,6 +162,14 @@ njs_leading_zeros64(uint64_t x)
 #endif
 
 
+#if (NJS_HAVE_GCC_ATTRIBUTE_NONSTRING)
+#define NJS_NONSTRING      __attribute__((nonstring))
+
+#else
+#define NJS_NONSTRING
+#endif
+
+
 #if (NJS_CLANG)
 /* Any __asm__ directive disables loop vectorization in GCC and Clang. */
 #define njs_pragma_loop_disable_vectorization  __asm__("")
diff --git a/src/njs_sprintf.c b/src/njs_sprintf.c
index 16ae9004e..d80fe396d 100644
--- a/src/njs_sprintf.c
+++ b/src/njs_sprintf.c
@@ -95,8 +95,8 @@ njs_vsprintf(u_char *buf, u_char *end, const char *fmt, va_list args)
     njs_bool_t     sign;
     njs_sprintf_t  spf;
 
-    static const u_char  hexadecimal[16] = "0123456789abcdef";
-    static const u_char  HEXADECIMAL[16] = "0123456789ABCDEF";
+    static const u_char  hexadecimal[16] NJS_NONSTRING = "0123456789abcdef";
+    static const u_char  HEXADECIMAL[16] NJS_NONSTRING = "0123456789ABCDEF";
     static const u_char  nan[] = "[nan]";
     static const u_char  infinity[] = "[infinity]";
 
diff --git a/src/njs_string.c b/src/njs_string.c
index 6a91cb4c4..8cee00396 100644
--- a/src/njs_string.c
+++ b/src/njs_string.c
@@ -309,7 +309,7 @@ njs_encode_hex(njs_str_t *dst, const njs_str_t *src)
     size_t        i, len;
     const u_char  *start;
 
-    static const u_char  hex[16] = "0123456789abcdef";
+    static const u_char  hex[16] NJS_NONSTRING = "0123456789abcdef";
 
     len = src->length;
     start = src->start;
diff --git a/src/njs_string.h b/src/njs_string.h
index 686a5a74e..f48302788 100644
--- a/src/njs_string.h
+++ b/src/njs_string.h
@@ -209,7 +209,7 @@ njs_string_encode(const uint32_t *escape, size_t size, const u_char *src,
     u_char *dst)
 {
     uint8_t              byte;
-    static const u_char  hex[16] = "0123456789ABCDEF";
+    static const u_char  hex[16] NJS_NONSTRING = "0123456789ABCDEF";
 
     do {
         byte = *src++;
diff --git a/src/qjs_buffer.c b/src/qjs_buffer.c
index a45f57ceb..a5cbf4c66 100644
--- a/src/qjs_buffer.c
+++ b/src/qjs_buffer.c
@@ -2354,7 +2354,7 @@ qjs_hex_encode(JSContext *ctx, const njs_str_t *src, njs_str_t *dst)
     size_t        i, len;
     const u_char  *start;
 
-    static const u_char  hex[16] = "0123456789abcdef";
+    static const u_char  hex[16] NJS_NONSTRING = "0123456789abcdef";
 
     len = src->length;
     start = src->start;