diff --git a/src/main/java/org/apache/commons/jxpath/ri/InfoSetUtil.java b/src/main/java/org/apache/commons/jxpath/ri/InfoSetUtil.java
index a5f337034..ac273a69f 100644
--- a/src/main/java/org/apache/commons/jxpath/ri/InfoSetUtil.java
+++ b/src/main/java/org/apache/commons/jxpath/ri/InfoSetUtil.java
@@ -98,7 +98,7 @@ public static double doubleValue(final Object object) {
             return ((Number) object).doubleValue();
         }
         if (object instanceof Boolean) {
-            return ((Boolean) object).booleanValue() ? 0.0 : 1.0;
+            return ((Boolean) object).booleanValue() ? 1.0 : 0.0;
         }
         if (object instanceof String) {
             if (object.equals("")) {
diff --git a/src/test/java/org/apache/commons/jxpath/ri/compiler/CoreFunctionTest.java b/src/test/java/org/apache/commons/jxpath/ri/compiler/CoreFunctionTest.java
index db68bde51..5b52dba36 100644
--- a/src/test/java/org/apache/commons/jxpath/ri/compiler/CoreFunctionTest.java
+++ b/src/test/java/org/apache/commons/jxpath/ri/compiler/CoreFunctionTest.java
@@ -114,6 +114,19 @@ void testCoreFunctions() {
         assertXPathValue(context, "round(2 div 0)", Double.valueOf(Double.POSITIVE_INFINITY));
     }
 
+    @Test
+    void testBooleanToNumberConversionIsXPathConformant() {
+        // XPath number(true())=1 and number(false())=0; the numeric coercion used by arithmetic,
+        // relational operators and floor/ceiling/round must agree with number(), not invert it.
+        assertXPathValue(context, "$bool_true + 1", Double.valueOf(2));
+        assertXPathValue(context, "$bool_false + 1", Double.valueOf(1));
+        assertXPathValue(context, "floor($bool_true)", Double.valueOf(1));
+        assertXPathValue(context, "ceiling($bool_false)", Double.valueOf(0));
+        assertXPathValue(context, "round($bool_true)", Double.valueOf(1));
+        assertXPathValue(context, "$bool_true > 0.5", Boolean.TRUE);
+        assertXPathValue(context, "$bool_false > 0.5", Boolean.FALSE);
+    }
+
     @Test
     void testNumberConversionIsXPathConformant() {
         // Java number literals that are outside the XPath 1.0 number grammar must convert to NaN.