diff --git a/core/src/main/java/org/teavm/cache/ClassIO.java b/core/src/main/java/org/teavm/cache/ClassIO.java
index 552805e2f..035baac07 100644
--- a/core/src/main/java/org/teavm/cache/ClassIO.java
+++ b/core/src/main/java/org/teavm/cache/ClassIO.java
@@ -118,7 +118,7 @@ public class ClassIO {
             output.writeUnsigned(0);
         } else if (value instanceof Integer) {
             output.writeUnsigned(1);
-            output.writeUnsigned((Integer) value);
+            output.writeSigned((Integer) value);
         } else if (value instanceof Long) {
             output.writeUnsigned(2);
             output.writeSigned((Long) value);
diff --git a/core/src/main/java/org/teavm/cache/VarDataInput.java b/core/src/main/java/org/teavm/cache/VarDataInput.java
index 0cd611066..2eac22206 100644
--- a/core/src/main/java/org/teavm/cache/VarDataInput.java
+++ b/core/src/main/java/org/teavm/cache/VarDataInput.java
@@ -45,7 +45,7 @@ public class VarDataInput {
 
     public int readSigned() throws IOException {
         int value = readUnsigned();
-        return (value & 1) == 0 ? (value >>> 1) : -(value >>> 1);
+        return (value & 1) == 0 ? (value >>> 1) : ~(value >>> 1);
     }
 
     public long readUnsignedLong() throws IOException {
@@ -65,7 +65,7 @@ public class VarDataInput {
 
     public long readSignedLong() throws IOException {
         long value = readUnsignedLong();
-        return (value & 1) == 0 ? (value >> 1) : -(value >> 1);
+        return (value & 1) == 0 ? (value >> 1) : ~(value >> 1);
     }
 
     public float readFloat() throws IOException {
@@ -106,7 +106,7 @@ public class VarDataInput {
         long bits = mantissa & ((1L << 52) - 1);
         bits |= (long) exponent << 52;
         if (sign) {
-            bits |= 1L << 53;
+            bits |= 1L << 63;
         }
 
         return Double.longBitsToDouble(bits);
diff --git a/core/src/main/java/org/teavm/cache/VarDataOutput.java b/core/src/main/java/org/teavm/cache/VarDataOutput.java
index e64405457..9d9e3da1d 100644
--- a/core/src/main/java/org/teavm/cache/VarDataOutput.java
+++ b/core/src/main/java/org/teavm/cache/VarDataOutput.java
@@ -37,7 +37,7 @@ public class VarDataOutput implements Closeable {
     }
 
     public void writeSigned(int value) throws IOException {
-        writeUnsigned(value < 0 ? ((-value) << 1) | 1 : value << 1);
+        writeUnsigned(value < 0 ? ((~value) << 1) | 1 : value << 1);
     }
 
     public void writeUnsigned(long value) throws IOException {
@@ -49,7 +49,7 @@ public class VarDataOutput implements Closeable {
     }
 
     public void writeSigned(long value) throws IOException {
-        writeUnsigned(value < 0 ? ((-value) << 1) | 1 : value << 1);
+        writeUnsigned(value < 0 ? ((~value) << 1) | 1 : value << 1);
     }
 
     public void writeFloat(float value) throws IOException {