diff --git a/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java b/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java
index 498b5a17b..ee3d6e04c 100644
--- a/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java
+++ b/teavm-classlib/src/main/java/org/teavm/classlib/java/lang/TAbstractStringBuilder.java
@@ -249,7 +249,7 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
             exp = 0;
             float digit = 1;
             for (int i = powersOfTen.length - 1; i >= 0; --i) {
-                if ((exp | bit) <= FLOAT_MAX_EXPONENT && powersOfTen[i] * digit  < value) {
+                if ((exp | bit) <= FLOAT_MAX_EXPONENT && powersOfTen[i] * digit <= value) {
                     digit *= powersOfTen[i];
                     exp |= bit;
                 }
@@ -290,7 +290,6 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
                 exp = 0;
             }
         }
-        sz += digits;
 
         // Extend buffer to store exponent
         if (exp != 0) {
@@ -303,6 +302,11 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
             }
         }
 
+        if (exp != 0 && digits == intPart) {
+            digits++;
+        }
+        sz += digits;
+
         // Print mantissa
         insertSpace(target, target + sz);
         if (negative) {
@@ -399,7 +403,7 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
             exp = 0;
             double digit = 1;
             for (int i = doublePowersOfTen.length - 1; i >= 0; --i) {
-                if ((exp | bit) <= DOUBLE_MAX_EXPONENT && doublePowersOfTen[i] * digit  < value) {
+                if ((exp | bit) <= DOUBLE_MAX_EXPONENT && doublePowersOfTen[i] * digit <= value) {
                     digit *= doublePowersOfTen[i];
                     exp |= bit;
                 }
@@ -440,7 +444,6 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
                 exp = 0;
             }
         }
-        sz += digits;
 
         // Extend buffer to store exponent
         if (exp != 0) {
@@ -456,6 +459,11 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
             }
         }
 
+        if (exp != 0 && digits == intPart) {
+            digits++;
+        }
+        sz += digits;
+
         // Print mantissa
         insertSpace(target, target + sz);
         if (negative) {
diff --git a/teavm-classlib/src/test/java/org/teavm/classlib/impl/unicode/UnicodeSupportTest.java b/teavm-classlib/src/test/java/org/teavm/classlib/impl/unicode/UnicodeSupportTest.java
index 802e0e123..4ff1315ea 100644
--- a/teavm-classlib/src/test/java/org/teavm/classlib/impl/unicode/UnicodeSupportTest.java
+++ b/teavm-classlib/src/test/java/org/teavm/classlib/impl/unicode/UnicodeSupportTest.java
@@ -1,9 +1,24 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
 package org.teavm.classlib.impl.unicode;
 
 import static org.junit.Assert.assertFalse;
+import org.junit.Test;
 
 public class UnicodeSupportTest {
-
     private static boolean pairsEqual(final int[] pairs, final int index1, final int index2) {
         return pairs[index1] == pairs[index2] && pairs[index1 + 1] == pairs[index2 + 1];
     }
@@ -16,5 +31,4 @@ public class UnicodeSupportTest {
             assertFalse(pairsEqual(digitValues, digitValues.length - 4, digitValues.length - 2));
         }
     }
-
 }