diff --git a/src/org/jruby/RubyFloat.java b/src/org/jruby/RubyFloat.java
index 2bd7c66..235c002 100644
--- a/src/org/jruby/RubyFloat.java
+++ b/src/org/jruby/RubyFloat.java
@@ -143,7 +143,7 @@ public class RubyFloat extends RubyNumeric {
     }

     public RubyFloat(Ruby runtime, double value) {
-        super(runtime, runtime.getFloat());
+        super(runtime, runtime.is1_9() && runtime.getInstanceConfig().PRECISE_DECIMAL ? runtime.getRational() : runtime.getFloat());
         this.value = value;
     }

diff --git a/src/org/jruby/RubyInstanceConfig.java b/src/org/jruby/RubyInstanceConfig.java
index 2e62eea..a6ab309 100644
--- a/src/org/jruby/RubyInstanceConfig.java
+++ b/src/org/jruby/RubyInstanceConfig.java
@@ -323,6 +323,8 @@ public class RubyInstanceConfig {
     public static final boolean JIT_LOADING_DEBUG = SafePropertyAccessor.getBoolean("jruby.jit.debug", false);

     public static final boolean CAN_SET_ACCESSIBLE = SafePropertyAccessor.getBoolean("jruby.ji.setAccessible", true);
+
+    public final boolean PRECISE_DECIMAL = SafePropertyAccessor.getBoolean("jruby.decimal.isPrecise", false);

     private TraceType traceType =
             TraceType.traceTypeFor(SafePropertyAccessor.getProperty("jruby.backtrace.style", "ruby_framed"));