diff --git a/compiler/cpp/src/globals.h b/compiler/cpp/src/globals.h
index b856a61..2b1865b 100644
--- a/compiler/cpp/src/globals.h
+++ b/compiler/cpp/src/globals.h
@@ -129,4 +129,13 @@
  */
 extern int g_allow_neg_field_keys;
 
+/**
+ * Whether or not 64-bit constants will generate a warning.
+ *
+ * Some languages don't support 64-bit constants, but many do, so we can
+ * suppress this warning for projects that don't use any non-64-bit-safe
+ * languages.
+ */
+extern int g_allow_64bit_consts;
+
 #endif
diff --git a/compiler/cpp/src/main.cc b/compiler/cpp/src/main.cc
index da86d0d..892ae20 100644
--- a/compiler/cpp/src/main.cc
+++ b/compiler/cpp/src/main.cc
@@ -157,6 +157,11 @@
 int g_allow_neg_field_keys;
 
 /**
+ * Whether or not 64-bit constants will generate a warning.
+ */
+int g_allow_64bit_consts = 0;
+
+/**
  * Flags to control code generation
  */
 bool gen_cpp = false;
@@ -647,6 +652,7 @@
   fprintf(stderr, "  --allow-neg-keys  Allow negative field keys (Used to "
           "preserve protocol\n");
   fprintf(stderr, "                compatibility with older .thrift files)\n");
+  fprintf(stderr, "  --allow-64bit-consts  Do not print warnings about using 64-bit constants\n");
   fprintf(stderr, "  --gen STR   Generate code with a dynamically-registered generator.\n");
   fprintf(stderr, "                STR has the form language[:key1=val1[,key2,[key3=val3]]].\n");
   fprintf(stderr, "                Keys and values are options passed to the generator.\n");
@@ -980,6 +986,8 @@
         gen_recurse = true;
       } else if (strcmp(arg, "-allow-neg-keys") == 0) {
         g_allow_neg_field_keys = true;
+      } else if (strcmp(arg, "-allow-64bit-consts") == 0) {
+        g_allow_64bit_consts = true;
       } else if (strcmp(arg, "-gen") == 0) {
         arg = argv[++i];
         if (arg == NULL) {
diff --git a/compiler/cpp/src/thrifty.yy b/compiler/cpp/src/thrifty.yy
index f50c1e2..c916604 100644
--- a/compiler/cpp/src/thrifty.yy
+++ b/compiler/cpp/src/thrifty.yy
@@ -618,7 +618,7 @@
       pdebug("ConstValue => tok_int_constant");
       $$ = new t_const_value();
       $$->set_integer($1);
-      if ($1 < INT32_MIN || $1 > INT32_MAX) {
+      if (!g_allow_64bit_consts && ($1 < INT32_MIN || $1 > INT32_MAX)) {
         pwarning(1, "64-bit constant \"%"PRIi64"\" may not work in all languages.\n", $1);
       }
     }