diff --git a/teavm-core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java b/teavm-core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java
index a065708fa..d71cec93d 100644
--- a/teavm-core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java
+++ b/teavm-core/src/main/java/org/teavm/dependency/DataFlowGraphBuilder.java
@@ -66,7 +66,7 @@ public class DataFlowGraphBuilder implements InstructionReader {
                 startNodes.add(i);
             }
             for (int pred : graph.incomingEdges(i)) {
-                if (importantNodes.contains(pred) && importantNodes.contains(i)) {
+                if (importantNodes.contains(classes.find(pred)) && importantNodes.contains(classes.find(i))) {
                     continue;
                 }
                 int newCls = classes.union(pred, i);
@@ -80,7 +80,7 @@ public class DataFlowGraphBuilder implements InstructionReader {
         for (int[] scc : sccs) {
             int last = -1;
             for (int node : scc) {
-                if (!importantNodes.contains(node)) {
+                if (!importantNodes.contains(classes.find(node))) {
                     continue;
                 }
                 last = last < 0 ? node : classes.union(node, last);
diff --git a/teavm-core/src/main/resources/org/teavm/javascript/runtime.js b/teavm-core/src/main/resources/org/teavm/javascript/runtime.js
index 797e95b19..b3629bfb5 100644
--- a/teavm-core/src/main/resources/org/teavm/javascript/runtime.js
+++ b/teavm-core/src/main/resources/org/teavm/javascript/runtime.js
@@ -605,7 +605,7 @@ function Long_toNumber(val) {
     return 0x100000000 * hi + lo;
 }
 function Long_add(a, b) {
-    if (a.hi === a.lo >> 31 && b.hi === b.lo >> 31) {
+    if (a.hi === (a.lo >> 31) && b.hi === (b.lo >> 31)) {
         return Long_fromNumber(a.lo + b.lo);
     }
     var a_lolo = a.lo & 0xFFFF;
@@ -643,7 +643,7 @@ function Long_neg(a) {
     return Long_inc(new Long(a.lo ^ 0xFFFFFFFF, a.hi ^ 0xFFFFFFFF));
 }
 function Long_sub(a, b) {
-    if (a.hi === 0 && a.lo >> 31 && b.hi === b.lo >> 31) {
+    if (a.hi === (a.lo >> 31) && b.hi === (b.lo >> 31)) {
         return Long_fromNumber(a.lo - b.lo);
     }
     var a_lolo = a.lo & 0xFFFF;