diff --git a/autotest/abs/abs.cpp b/autotest/abs/abs.cpp
index f2fc0e1cf..961549cd4 100644
--- a/autotest/abs/abs.cpp
+++ b/autotest/abs/abs.cpp
@@ -2,13 +2,28 @@
 
 using namespace Upp;
 
+bool FltMatch(double x, double y)
+{
+	return abs(x - y) < min(abs(x), abs(y)) / 1e5;
+}
+
+bool DblMatch(double x, double y)
+{
+	return abs(x - y) < min(abs(x), abs(y)) / 1e10;
+}
+
 CONSOLE_APP_MAIN
 {
-	ASSERT(abs(-1) == 1);
-	ASSERT(abs((int16)-1) == 1);
-	ASSERT(abs((int64)-1) == 1);
-	ASSERT(abs((int8)-1) == 1);
-	ASSERT(abs((float)-1) == 1);
-	ASSERT(abs((double)-1) == 1);
-	LOG("OK");
+	StdLogSetup(LOG_COUT|LOG_FILE);
+
+	ASSERT(abs(-0x40000000) == 0x40000000);
+	ASSERT(abs((int16)-0x4000) == 0x4000);
+	ASSERT(abs((int64)-0x400000000000) == 0x400000000000);
+	ASSERT(abs((int8)-0x40) == 0x40);
+	ASSERT(FltMatch(abs((float)-1.1), 1.1));
+	ASSERT(DblMatch(abs((double)-1.1), 1.1));
+	
+	ASSERT(abs(Complex(3, -4)) == 5);
+
+	LOG("=============== OK");
 }