diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TDouble.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TDouble.java
index bc9464aea..329c42b3e 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/lang/TDouble.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TDouble.java
@@ -121,7 +121,7 @@ public class TDouble extends TNumber implements TComparable<TDouble> {
                 if (c < '0' || c > '9') {
                     break;
                 }
-                if (mantissa < 1E17) {
+                if (mantissa < TLong.MAX_VALUE / 10 - 9) {
                     mantissa = mantissa * 10 + (c - '0');
                 } else {
                     ++exp;
@@ -136,7 +136,7 @@ public class TDouble extends TNumber implements TComparable<TDouble> {
                 if (c < '0' || c > '9') {
                     break;
                 }
-                if (mantissa < 1E17) {
+                if (mantissa < TLong.MAX_VALUE / 10 - 9) {
                     mantissa = mantissa * 10 + (c - '0');
                     --exp;
                 }
diff --git a/classlib/src/main/java/org/teavm/classlib/java/lang/TFloat.java b/classlib/src/main/java/org/teavm/classlib/java/lang/TFloat.java
index 8961b9f83..d5d5a1d9c 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/lang/TFloat.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/lang/TFloat.java
@@ -167,7 +167,7 @@ public class TFloat extends TNumber implements TComparable<TFloat> {
                 if (c < '0' || c > '9') {
                     break;
                 }
-                if (mantissa < 1E8) {
+                if (mantissa < (TInteger.MAX_VALUE / 10) - 9) {
                     mantissa = mantissa * 10 + (c - '0');
                 } else {
                     ++exp;
@@ -183,7 +183,7 @@ public class TFloat extends TNumber implements TComparable<TFloat> {
                 if (c < '0' || c > '9') {
                     break;
                 }
-                if (mantissa < 1E38) {
+                if (mantissa < (TInteger.MAX_VALUE / 10) - 9) {
                     mantissa = mantissa * 10 + (c - '0');
                     --exp;
                 }
diff --git a/tests/src/test/java/org/teavm/classlib/java/lang/DoubleTest.java b/tests/src/test/java/org/teavm/classlib/java/lang/DoubleTest.java
index 348768869..4bd0e4087 100644
--- a/tests/src/test/java/org/teavm/classlib/java/lang/DoubleTest.java
+++ b/tests/src/test/java/org/teavm/classlib/java/lang/DoubleTest.java
@@ -49,6 +49,9 @@ public class DoubleTest {
         assertEquals(0, Double.parseDouble("23E-8000"), 1E-12);
         assertEquals(0, Double.parseDouble("00000"), 1E-12);
         assertEquals(0, Double.parseDouble("00000.0000"), 1E-12);
+
+        assertEquals(4499999999999888888888888.0, Double.parseDouble("4499999999999888888888888"), 1E9);
+        assertEquals(0.4499999999999888888888888, Double.parseDouble("0.4499999999999888888888888"), 1E-15);
     }
 
     @Test
diff --git a/tests/src/test/java/org/teavm/classlib/java/lang/FloatTest.java b/tests/src/test/java/org/teavm/classlib/java/lang/FloatTest.java
index 1824984bb..4690f17bd 100644
--- a/tests/src/test/java/org/teavm/classlib/java/lang/FloatTest.java
+++ b/tests/src/test/java/org/teavm/classlib/java/lang/FloatTest.java
@@ -50,6 +50,8 @@ public class FloatTest {
         assertEquals(0, Float.parseFloat("23E-8000"), 1E-12F);
         assertEquals(0, Float.parseFloat("00000"), 1E-12F);
         assertEquals(0, Float.parseFloat("00000.0000"), 1E-12F);
+        assertEquals(4499999285F, Float.parseFloat("4499999285"), 100F);
+        assertEquals(0.4499999285F, Float.parseFloat("0.4499999285"), 1E-9F);
     }
 
     @Test