diff --git a/consensus/replay.go b/consensus/replay.go
index 4557a7d05..d3ea91885 100644
--- a/consensus/replay.go
+++ b/consensus/replay.go
@@ -117,6 +117,7 @@ func (cs *ConsensusState) catchupReplay(csHeight int) error {
 	} else {
 		defer func() {
 			if err := gr.Close(); err != nil {
+				cs.Logger.Error("Error closing wal Search", "err", err)
 				return
 			}
 		}()
diff --git a/consensus/replay_test.go b/consensus/replay_test.go
index 992201cdf..9e4dbb843 100644
--- a/consensus/replay_test.go
+++ b/consensus/replay_test.go
@@ -492,6 +492,7 @@ func makeBlockchainFromWAL(wal WAL) ([]*types.Block, []*types.Commit, error) {
 	}
 	defer func() {
 		if err := gr.Close(); err != nil {
+			wal.Logger.Error("Error closing wal Search", "err", err)
 			return
 		}
 	}()
diff --git a/consensus/wal.go b/consensus/wal.go
index 3f85f7da6..1d2c74e34 100644
--- a/consensus/wal.go
+++ b/consensus/wal.go
@@ -174,7 +174,6 @@ func (wal *baseWAL) SearchForEndHeight(height uint64) (gr *auto.GroupReader, fou
 				}
 			}
 		}
-
 		gr.Close()
 	}
 
diff --git a/mempool/mempool.go b/mempool/mempool.go
index d1475f331..ef2fa4950 100644
--- a/mempool/mempool.go
+++ b/mempool/mempool.go
@@ -3,6 +3,7 @@ package mempool
 import (
 	"bytes"
 	"container/list"
+	"fmt"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -191,11 +192,11 @@ func (mem *Mempool) CheckTx(tx types.Tx, cb func(*abci.Response)) (err error) {
 		// TODO: Notify administrators when WAL fails
 		_, err := mem.wal.Write([]byte(tx))
 		if err != nil {
-			return err
+			mem.logger.Error(fmt.Sprintf("Error writing to WAL: %v", err))
 		}
 		_, err = mem.wal.Write([]byte("\n"))
 		if err != nil {
-			return err
+			mem.logger.Error(fmt.Sprintf("Error writing to WAL: %v", err))
 		}
 	}
 	// END WAL
@@ -337,9 +338,9 @@ func (mem *Mempool) collectTxs(maxTxs int) types.Txs {
 // Update informs the mempool that the given txs were committed and can be discarded.
 // NOTE: this should be called *after* block is committed by consensus.
 // NOTE: unsafe; Lock/Unlock must be managed by caller
-func (mem *Mempool) Update(height int, txs types.Txs) {
+func (mem *Mempool) Update(height int, txs types.Txs) error {
 	if err := mem.proxyAppConn.FlushSync(); err != nil { // To flush async resCb calls e.g. from CheckTx
-		panic(err)
+		return err
 	}
 	// First, create a lookup map of txns in new txs.
 	txsMap := make(map[string]struct{})
@@ -363,6 +364,7 @@ func (mem *Mempool) Update(height int, txs types.Txs) {
 		// mem.recheckCursor re-scans mem.txs and possibly removes some txs.
 		// Before mem.Reap(), we should wait for mem.recheckCursor to be nil.
 	}
+	return nil
 }
 
 func (mem *Mempool) filterTxs(blockTxsMap map[string]struct{}) []types.Tx {
diff --git a/p2p/upnp/upnp.go b/p2p/upnp/upnp.go
index a90b10044..43e943480 100644
--- a/p2p/upnp/upnp.go
+++ b/p2p/upnp/upnp.go
@@ -40,11 +40,7 @@ func Discover() (nat NAT, err error) {
 		return
 	}
 	socket := conn.(*net.UDPConn)
-	defer func() {
-		if err := socket.Close(); err != nil {
-			return
-		}
-	}()
+	defer socket.Close()
 
 	if err := socket.SetDeadline(time.Now().Add(3 * time.Second)); err != nil {
 		return nil, err
@@ -201,11 +197,8 @@ func getServiceURL(rootURL string) (url, urnDomain string, err error) {
 	if err != nil {
 		return
 	}
-	defer func() {
-		if err := r.Body.Close(); err != nil {
-			return
-		}
-	}()
+	defer r.Body.Close()
+
 	if r.StatusCode >= 400 {
 		err = errors.New(string(r.StatusCode))
 		return
@@ -303,11 +296,7 @@ func (n *upnpNAT) getExternalIPAddress() (info statusInfo, err error) {
 	var response *http.Response
 	response, err = soapRequest(n.serviceURL, "GetExternalIPAddress", message, n.urnDomain)
 	if response != nil {
-		defer func() {
-			if err := response.Body.Close(); err != nil {
-				return
-			}
-		}()
+		defer response.Body.Close()
 	}
 	if err != nil {
 		return
@@ -356,11 +345,7 @@ func (n *upnpNAT) AddPortMapping(protocol string, externalPort, internalPort int
 	var response *http.Response
 	response, err = soapRequest(n.serviceURL, "AddPortMapping", message, n.urnDomain)
 	if response != nil {
-		defer func() {
-			if err := response.Body.Close(); err != nil {
-				return
-			}
-		}()
+		defer response.Body.Close()
 	}
 	if err != nil {
 		return
@@ -386,11 +371,7 @@ func (n *upnpNAT) DeletePortMapping(protocol string, externalPort, internalPort
 	var response *http.Response
 	response, err = soapRequest(n.serviceURL, "DeletePortMapping", message, n.urnDomain)
 	if response != nil {
-		defer func() {
-			if err := response.Body.Close(); err != nil {
-				return
-			}
-		}()
+		defer response.Body.Close()
 	}
 	if err != nil {
 		return
diff --git a/rpc/lib/client/http_client.go b/rpc/lib/client/http_client.go
index bfbae84c5..ea025818d 100644
--- a/rpc/lib/client/http_client.go
+++ b/rpc/lib/client/http_client.go
@@ -93,12 +93,8 @@ func (c *JSONRPCClient) Call(method string, params map[string]interface{}, resul
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		if err := httpResponse.Body.Close(); err != nil {
-			panic(err)
-			return
-		}
-	}()
+	defer httpResponse.Body.Close()
+
 	responseBytes, err := ioutil.ReadAll(httpResponse.Body)
 	if err != nil {
 		return nil, err
@@ -133,12 +129,8 @@ func (c *URIClient) Call(method string, params map[string]interface{}, result in
 	if err != nil {
 		return nil, err
 	}
-	defer func() {
-		if err := resp.Body.Close(); err != nil {
-			panic(err)
-			return
-		}
-	}()
+	defer resp.Body.Close()
+
 	responseBytes, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
diff --git a/rpc/lib/client/ws_client.go b/rpc/lib/client/ws_client.go
index 3bfcbf9fd..0b3ec2b8c 100644
--- a/rpc/lib/client/ws_client.go
+++ b/rpc/lib/client/ws_client.go
@@ -291,7 +291,7 @@ func (c *WSClient) processBacklog() error {
 	case request := <-c.backlog:
 		if c.writeWait > 0 {
 			if err := c.conn.SetWriteDeadline(time.Now().Add(c.writeWait)); err != nil {
-				panic(err)
+				c.Logger.Error("failed to set write deadline", "err", err)
 			}
 		}
 		if err := c.conn.WriteJSON(request); err != nil {
@@ -363,7 +363,7 @@ func (c *WSClient) writeRoutine() {
 		case request := <-c.send:
 			if c.writeWait > 0 {
 				if err := c.conn.SetWriteDeadline(time.Now().Add(c.writeWait)); err != nil {
-					panic(err)
+					c.Logger.Error("failed to set write deadline", "err", err)
 				}
 			}
 			if err := c.conn.WriteJSON(request); err != nil {
@@ -376,7 +376,7 @@ func (c *WSClient) writeRoutine() {
 		case <-ticker.C:
 			if c.writeWait > 0 {
 				if err := c.conn.SetWriteDeadline(time.Now().Add(c.writeWait)); err != nil {
-					panic(err)
+					c.Logger.Error("failed to set write deadline", "err", err)
 				}
 			}
 			if err := c.conn.WriteMessage(websocket.PingMessage, []byte{}); err != nil {
@@ -392,7 +392,7 @@ func (c *WSClient) writeRoutine() {
 			return
 		case <-c.Quit:
 			if err := c.conn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseNormalClosure, "")); err != nil {
-				panic(err)
+				c.Logger.Error("failed to write message", "err", err)
 			}
 			return
 		}
@@ -424,7 +424,7 @@ func (c *WSClient) readRoutine() {
 		// reset deadline for every message type (control or data)
 		if c.readWait > 0 {
 			if err := c.conn.SetReadDeadline(time.Now().Add(c.readWait)); err != nil {
-				panic(err)
+				c.Logger.Error("failed to set read deadline", "err", err)
 			}
 		}
 		_, data, err := c.conn.ReadMessage()
diff --git a/rpc/lib/server/handlers.go b/rpc/lib/server/handlers.go
index 33cc00f2b..d9ab4790b 100644
--- a/rpc/lib/server/handlers.go
+++ b/rpc/lib/server/handlers.go
@@ -534,6 +534,7 @@ func (wsc *wsConnection) readRoutine() {
 			}
 		}
 	}()
+	defer wsc.baseConn.Close()
 
 	wsc.baseConn.SetPongHandler(func(m string) error {
 		return wsc.baseConn.SetReadDeadline(time.Now().Add(wsc.readWait))
@@ -546,7 +547,7 @@ func (wsc *wsConnection) readRoutine() {
 		default:
 			// reset deadline for every type of message (control or data)
 			if err := wsc.baseConn.SetReadDeadline(time.Now().Add(wsc.readWait)); err != nil {
-				panic(err)
+				wsc.Logger.Error("failed to set read deadline", "err", err)
 			}
 			var in []byte
 			_, in, err := wsc.baseConn.ReadMessage()
@@ -619,9 +620,7 @@ func (wsc *wsConnection) writeRoutine() {
 	pingTicker := time.NewTicker(wsc.pingPeriod)
 	defer func() {
 		pingTicker.Stop()
-		if err := wsc.baseConn.Close(); err != nil {
-			panic(err)
-		}
+		wsc.baseConn.Close()
 	}()
 
 	// https://github.com/gorilla/websocket/issues/97
@@ -781,6 +780,6 @@ func writeListOfEndpoints(w http.ResponseWriter, r *http.Request, funcMap map[st
 	w.WriteHeader(200)
 	_, err := w.Write(buf.Bytes())
 	if err != nil {
-		panic(err)
+		// ignore error
 	}
 }
diff --git a/rpc/lib/server/http_server.go b/rpc/lib/server/http_server.go
index a0f6d9acf..e918192b6 100644
--- a/rpc/lib/server/http_server.go
+++ b/rpc/lib/server/http_server.go
@@ -58,7 +58,7 @@ func WriteRPCResponseHTTPError(w http.ResponseWriter, httpCode int, res types.RP
 	w.WriteHeader(httpCode)
 	_, err = w.Write(jsonBytes)
 	if err != nil {
-		panic(err)
+		// ignore error
 	}
 }
 
@@ -71,7 +71,7 @@ func WriteRPCResponseHTTP(w http.ResponseWriter, res types.RPCResponse) {
 	w.WriteHeader(200)
 	_, err = w.Write(jsonBytes)
 	if err != nil {
-		panic(err)
+		// ignore error
 	}
 }
 
diff --git a/state/execution.go b/state/execution.go
index a94bbdbf7..40169bcf7 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -288,10 +288,11 @@ func (s *State) indexTxs(abciResponses *ABCIResponses) {
 			Tx:     tx,
 			Result: *d,
 		}); err != nil {
-			panic(err)
+			s.logger.Error("Error with batch.Add", "err", err)
 		}
 	}
 	if err := s.TxIndexer.AddBatch(batch); err != nil {
+		s.logger.Error("Error adding batch", "err", err)
 		panic(err)
 	}
 }
diff --git a/types/part_set.go b/types/part_set.go
index b68d05309..46387e353 100644
--- a/types/part_set.go
+++ b/types/part_set.go
@@ -36,7 +36,7 @@ func (part *Part) Hash() []byte {
 		hasher := ripemd160.New()
 		_, err := hasher.Write(part.Bytes)
 		if err != nil {
-			panic(err)
+			// ignore error
 		}
 		part.hash = hasher.Sum(nil)
 		return part.hash
diff --git a/types/services.go b/types/services.go
index e34d846b5..f025de79b 100644
--- a/types/services.go
+++ b/types/services.go
@@ -25,7 +25,7 @@ type Mempool interface {
 	Size() int
 	CheckTx(Tx, func(*abci.Response)) error
 	Reap(int) Txs
-	Update(height int, txs Txs)
+	Update(height int, txs Txs) error
 	Flush()
 
 	TxsAvailable() <-chan int
@@ -42,7 +42,7 @@ func (m MockMempool) Unlock()                                      {}
 func (m MockMempool) Size() int                                    { return 0 }
 func (m MockMempool) CheckTx(tx Tx, cb func(*abci.Response)) error { return nil }
 func (m MockMempool) Reap(n int) Txs                               { return Txs{} }
-func (m MockMempool) Update(height int, txs Txs)                   {}
+func (m MockMempool) Update(height int, txs Txs) error             { return nil }
 func (m MockMempool) Flush()                                       {}
 func (m MockMempool) TxsAvailable() <-chan int                     { return make(chan int) }
 func (m MockMempool) EnableTxsAvailable()                          {}