diff --git a/src/dynpmc/rational.pmc b/src/dynpmc/rational.pmc
index 7db3090..a051768 100644
--- a/src/dynpmc/rational.pmc
+++ b/src/dynpmc/rational.pmc
@@ -397,7 +397,7 @@ Returns the version of GNU Multiple Precision library. Returns 0.0.0, if GMP is
 */
     VTABLE INTVAL get_bool() {
       #ifdef PARROT_HAS_GMP
-        if (mpq_cmp_si(RT(SELF), 0, 0))
+        if (mpq_cmp_si(RT(SELF), 0, 1) == 0)
             return 0;
         else
             return 1;
diff --git a/t/dynpmc/rational.t b/t/dynpmc/rational.t
index 009120e..281ebce 100644
--- a/t/dynpmc/rational.t
+++ b/t/dynpmc/rational.t
@@ -25,7 +25,7 @@ Tests the Rational PMC.
     $S0 = config_hash['gmp']
 
     unless $S0 goto no_gmp
-    plan(78)
+    plan(79)
     loadlib $P1, 'rational'
     test_init()
     test_destroy()
@@ -559,7 +559,7 @@ CODE
 
 .sub test_init
     new $P1, 'Rational'
-    ok($P1,'initialization')
+    is($P1, 0, 'initialization')
 .end
 
 .sub test_destroy
@@ -669,8 +669,10 @@ CODE
     new $P0, 'Rational'
     $P0 = "0"
     $I0 = isfalse $P0
-
-    todo($I0, "0 value of rational does not evaluate correctly")
+    ok($I0, '0 should be false')
+    $P0 = "3/4"
+    $I0 = istrue $P0
+    ok($I0, '3/4 should be true')
 .end
 
 # Local Variables: