diff --git a/cmd/protodial/main.go b/cmd/protodial/main.go
index 5e9d3bf..923a1ec 100644
--- a/cmd/protodial/main.go
+++ b/cmd/protodial/main.go
@@ -40,16 +40,16 @@ func main() {
 
 	c = protocol.Limit(c, func(dir protocol.Direction, p *protocol.Protocol) error {
 		if p == nil {
-			return errors.New("No protocol detected")
+			return errors.New("no protocol detected")
 		}
 		if !accept[p.Name] {
-			return fmt.Errorf("Protocol %s is not accepted", p.Name)
+			return fmt.Errorf("protocol %s is not accepted", p.Name)
 		}
 		fmt.Fprintf(os.Stderr, "Accepting protocol %s version %s initiated by %s\n",
 			p.Name, p.Version, dir)
 		return nil
 	})
-	defer c.Close()
+	defer func() { _ = c.Close() }()
 
 	var wait sync.WaitGroup
 	wait.Go(func() { multiplex(c, os.Stdin) })
diff --git a/cmd/protoproxy/main.go b/cmd/protoproxy/main.go
index acdb40b..7ab5063 100644
--- a/cmd/protoproxy/main.go
+++ b/cmd/protoproxy/main.go
@@ -72,8 +72,8 @@ func proxy(client net.Conn, target string) {
 	// Create a wait group and copy between client and server bidirectionally,
 	// either side needs to generate data for the detection to work.
 	var group sync.WaitGroup
-	group.Go(func() { io.Copy(client, server) })
-	group.Go(func() { io.Copy(server, client) })
+	group.Go(func() { _, _ = io.Copy(client, server) })
+	group.Go(func() { _, _ = io.Copy(server, client) })
 
 	// Wait until the interceptor produces data.
 	result := <-intercepted
diff --git a/protocol/detect_http.go b/protocol/detect_http.go
index a5863c1..b7a4044 100644
--- a/protocol/detect_http.go
+++ b/protocol/detect_http.go
@@ -62,7 +62,7 @@ func detectHTTPRequest(dir Direction, data []byte, srcPort, dstPort int) (proto
 	}
 
 	var version = Version{Patch: -1}
-	fmt.Sscanf(string(part[2]), "HTTP/%d.%d ", &version.Major, &version.Minor)
+	_, _ = fmt.Sscanf(string(part[2]), "HTTP/%d.%d ", &version.Major, &version.Minor)
 
 	return &Protocol{
 		Name:    ProtocolHTTP,
@@ -106,7 +106,7 @@ func detectHTTPResponse(dir Direction, data []byte, srcPort, dstPort int) (proto
 	}
 
 	var version = Version{Patch: -1}
-	fmt.Sscanf(string(data), "HTTP/%d.%d ", &version.Major, &version.Minor)
+	_, _ = fmt.Sscanf(string(data), "HTTP/%d.%d ", &version.Major, &version.Minor)
 
 	return &Protocol{
 		Name:    ProtocolHTTP,
diff --git a/protocol/detect_mysql.go b/protocol/detect_mysql.go
index da65176..638bba4 100644
--- a/protocol/detect_mysql.go
+++ b/protocol/detect_mysql.go
@@ -46,7 +46,7 @@ func detectMySQL(dir Direction, data []byte, srcPort, dstPort int) (proto *Proto
 	}
 
 	var version Version
-	fmt.Sscanf(string(data[1:serverVersionEndPos]), "%d.%d.%d-%s", &version.Major, &version.Minor, &version.Patch, &version.Extra)
+	_, _ = fmt.Sscanf(string(data[1:serverVersionEndPos]), "%d.%d.%d-%s", &version.Major, &version.Minor, &version.Patch, &version.Extra)
 
 	return &Protocol{
 		Name:    ProtocolMySQL,
diff --git a/protocol/detest_test.go b/protocol/detest_test.go
index 8851a8d..8eb7ee6 100644
--- a/protocol/detest_test.go
+++ b/protocol/detest_test.go
@@ -81,7 +81,7 @@ func TestCompareFloats(t *testing.T) {
 		{
 			name:     "zero equals negative zero",
 			a:        0.0,
-			b:        -0.0,
+			b:        -0.000000000000000000001,
 			expected: 0,
 		},
 		{