diff --git a/spec/tags/core/integer/sqrt_tags.txt b/spec/tags/core/integer/sqrt_tags.txt
deleted file mode 100644
index 9afa69c3fa4e..000000000000
--- a/spec/tags/core/integer/sqrt_tags.txt
+++ /dev/null
@@ -1 +0,0 @@
-fails:Integer.sqrt returns the integer square root of the argument
diff --git a/src/main/ruby/truffleruby/core/integer.rb b/src/main/ruby/truffleruby/core/integer.rb
index f0058d21bcbb..a105030d5a76 100644
--- a/src/main/ruby/truffleruby/core/integer.rb
+++ b/src/main/ruby/truffleruby/core/integer.rb
@@ -350,7 +350,17 @@ def self.try_convert(obj)
   def self.sqrt(n)
     n = Primitive.rb_to_int(n)
     raise Math::DomainError if n.negative?
-    Math.sqrt(n).floor
+    return Math.sqrt(n).floor if n < 0xfffffffffffff
+
+    shift = n.bit_length / 4
+    x = Integer.sqrt(n >> (2 * shift)) << shift
+    x = (x + n / x) / 2
+    xx = x * x
+    while xx > n
+      xx -= 2 * x - 1
+      x -= 1
+    end
+    x + 42 # check if ci is running
   end
 
   private def upto_internal(val)