diff --git a/vlib/builtin/int.v b/vlib/builtin/int.v
index c1ba5b617d..989826bc11 100644
--- a/vlib/builtin/int.v
+++ b/vlib/builtin/int.v
@@ -4,6 +4,12 @@
 
 module builtin
 
+#include <float.h>
+
+import const (
+	DBL_EPSILON
+)
+
 pub fn (d double) str() string {
 	buf := malloc(sizeof(double) * 5 + 1)// TODO
 	C.sprintf(buf, '%f', d)
@@ -28,6 +34,11 @@ pub fn ptr_str(ptr voidptr) string {
 	return tos(buf, strlen(buf))
 }
 
+// compare floats using C epsilon
+pub fn (a f64) eq(b f64) bool {
+	return C.fabs(a - b) <= DBL_EPSILON	
+}
+
 // fn (nn i32) str() string {
 // return i
 // }
diff --git a/vlib/math/complex_test.v b/vlib/math/complex_test.v
index c42fcc4f96..bff6addc63 100644
--- a/vlib/math/complex_test.v
+++ b/vlib/math/complex_test.v
@@ -115,8 +115,8 @@ fn test_complex_abs() {
 	mut c1 := cmplx.complex(3,4)
 	assert c1.abs() == 5
 	c1 = cmplx.complex(1,2)
-	assert c1.abs() == math.sqrt(5)
-	assert c1.abs() == c1.conjugate().abs()
+	assert c1.abs().eq(math.sqrt(5))
+	assert c1.abs().eq(c1.conjugate().abs())
 	c1 = cmplx.complex(7,0)
 	assert c1.abs() == 7
 }
@@ -125,17 +125,17 @@ fn test_complex_angle(){
 	// Test is based on and verified from practice examples of Khan Academy 
 	// https://www.khanacademy.org/math/precalculus/imaginary-and-complex-numbers
 	mut c := cmplx.complex(1, 0)
-	assert c.angle() * 180 / math.Pi == 0
+	assert (c.angle() * 180 / math.Pi).eq(0)
 	c = cmplx.complex(1, 1)
-	assert c.angle() * 180 / math.Pi == 45
+	assert (c.angle() * 180 / math.Pi).eq(45)
 	c = cmplx.complex(0, 1)
-	assert c.angle() * 180 / math.Pi == 90
+	assert (c.angle() * 180 / math.Pi).eq(90)
 	c = cmplx.complex(-1, 1)
-	assert c.angle() * 180 / math.Pi == 135
+	assert (c.angle() * 180 / math.Pi).eq(135)
 	c = cmplx.complex(-1, -1)
-	assert c.angle() * 180 / math.Pi == -135
+	assert (c.angle() * 180 / math.Pi).eq(-135)
 	mut cc := c.conjugate()
-	assert cc.angle() + c.angle() == 0
+	assert (cc.angle() + c.angle()).eq(0)
 }
 
 
diff --git a/vlib/math/math_test.v b/vlib/math/math_test.v
index a7abd8124e..de45a0eda4 100644
--- a/vlib/math/math_test.v
+++ b/vlib/math/math_test.v
@@ -35,10 +35,10 @@ fn test_factorial() {
 
 fn test_erf() {
 	assert math.erf(0) == 0
-	assert math.erf(1.5) + math.erf(-1.5) == 0
+	assert (math.erf(1.5) + math.erf(-1.5)).eq(0)
 	assert math.erfc(0) == 1
-	assert math.erf(2.5) + math.erfc(2.5) == 1
-	assert math.erfc(3.6) + math.erfc(-3.6) == 2
+	assert (math.erf(2.5) + math.erfc(2.5)).eq(1)
+	assert (math.erfc(3.6) + math.erfc(-3.6)).eq(2)
 }
 
 fn test_gamma() {