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-core/src/main/java/org/teavm/vm/TeaVM.java b/teavm-core/src/main/java/org/teavm/vm/TeaVM.java
index 409841019..53d5efb6f 100644
--- a/teavm-core/src/main/java/org/teavm/vm/TeaVM.java
+++ b/teavm-core/src/main/java/org/teavm/vm/TeaVM.java
@@ -444,10 +444,6 @@ public class TeaVM implements TeaVMHost, ServiceRepository {
                 } else {
                     sourceWriter.append(asyncMethod ? naming.getFullNameForAsync(ref) : naming.getFullNameFor(ref));
                 }
-
-                if (wrapAsync) {
-                    sourceWriter.append(")");
-                }
                 sourceWriter.append(";").newLine();
             }
             for (Map.Entry<String, String> entry : exportedClasses.entrySet()) {
diff --git a/teavm-tests/src/test/java/org/teavm/classlib/java/lang/StringBuilderTest.java b/teavm-tests/src/test/java/org/teavm/classlib/java/lang/StringBuilderTest.java
index df50934c8..3f88af2aa 100644
--- a/teavm-tests/src/test/java/org/teavm/classlib/java/lang/StringBuilderTest.java
+++ b/teavm-tests/src/test/java/org/teavm/classlib/java/lang/StringBuilderTest.java
@@ -225,6 +225,37 @@ public class StringBuilderTest {
         assertEquals("1.23456789E150", sb.toString());
     }
 
+    @Test
+    public void powTenDoubleAppended() {
+        StringBuilder sb = new StringBuilder();
+        sb.append(10.0);
+        assertEquals("10.0", sb.toString());
+        sb.setLength(0);
+        sb.append(20.0);
+        assertEquals("20.0", sb.toString());
+        sb.setLength(0);
+        sb.append(100.0);
+        assertEquals("100.0", sb.toString());
+        sb.setLength(0);
+        sb.append(1000.0);
+        assertEquals("1000.0", sb.toString());
+        sb.setLength(0);
+        sb.append(0.1);
+        assertEquals("0.1", sb.toString());
+        sb.setLength(0);
+        sb.append(0.01);
+        assertEquals("0.01", sb.toString());
+        sb.setLength(0);
+        sb.append(1e20);
+        assertEquals("1.0E20", sb.toString());
+        sb.setLength(0);
+        sb.append(2e20);
+        assertEquals("2.0E20", sb.toString());
+        sb.setLength(0);
+        sb.append(1e-12);
+        assertEquals("1.0E-12", sb.toString());
+    }
+
     @Test
     public void negativeDoubleAppended() {
         StringBuilder sb = new StringBuilder();