diff --git a/src/lambda-calculus.js b/src/lambda-calculus.js
index aa117e6..926541a 100644
--- a/src/lambda-calculus.js
+++ b/src/lambda-calculus.js
@@ -133,7 +133,9 @@ export function fromInt(n) {
 export function toInt(term) {
   try {
     if ( config.numEncoding === "Church" ) {
-      return term ( x => x+1 ) ( Primitive(0) );
+      const succ = x => x+1 ;
+      const result = term ( succ ) ;
+      return result ( result === succ ? 0 : Primitive(0) );
     } else if ( config.numEncoding === "Scott" ) {
       let result = 0, evaluating = true;
       while ( evaluating )
diff --git a/tests/basics-church/test.js b/tests/basics-church/test.js
index 4207276..8ff1b8d 100644
--- a/tests/basics-church/test.js
+++ b/tests/basics-church/test.js
@@ -36,5 +36,6 @@ describe("Church tests",function(){
     assert.equal( times(1e2)(1e1), 1e3 );
     assert.equal( pow(10)(3), 1e3 );
     assert.equal( pred(pow(10)(3)), 1e3-1 );
+    assert.equal( pow(0)(0), 1);
   });
 });