diff --git a/src/core/coap/coap.cpp b/src/core/coap/coap.cpp
index 7f0aedeaa..82ce9fa4d 100644
--- a/src/core/coap/coap.cpp
+++ b/src/core/coap/coap.cpp
@@ -661,8 +661,6 @@ exit:
             cachedResponse->Free();
         }
     }
-
-    return;
 }
 
 CoapMetadata::CoapMetadata(bool                    aConfirmable,
diff --git a/src/core/net/dns_client.cpp b/src/core/net/dns_client.cpp
index d8295d00b..a48ee4c46 100644
--- a/src/core/net/dns_client.cpp
+++ b/src/core/net/dns_client.cpp
@@ -508,8 +508,6 @@ exit:
     {
         FinalizeDnsTransaction(*message, queryMetadata, NULL, 0, error);
     }
-
-    return;
 }
 
 } // namespace Dns
diff --git a/src/core/net/sntp_client.cpp b/src/core/net/sntp_client.cpp
index 102783c01..6c0f7a4c2 100644
--- a/src/core/net/sntp_client.cpp
+++ b/src/core/net/sntp_client.cpp
@@ -384,8 +384,6 @@ exit:
     {
         FinalizeSntpTransaction(*message, queryMetadata, 0, error);
     }
-
-    return;
 }
 
 } // namespace Sntp
diff --git a/src/core/thread/address_resolver.cpp b/src/core/thread/address_resolver.cpp
index 3cd7a4842..f9e643188 100644
--- a/src/core/thread/address_resolver.cpp
+++ b/src/core/thread/address_resolver.cpp
@@ -580,8 +580,6 @@ exit:
     {
         otLogWarnArp("Error while processing address error notification: %s", otThreadErrorToString(error));
     }
-
-    return;
 }
 
 void AddressResolver::HandleAddressQuery(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo)
diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index 48ce6efe9..a4aee00fb 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -4012,8 +4012,6 @@ exit:
 
     // send announce after received address solicit reply if needed
     InformPreviousChannel();
-
-    return;
 }
 
 void MleRouter::HandleAddressSolicit(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo)
diff --git a/src/core/thread/network_data_leader_ftd.cpp b/src/core/thread/network_data_leader_ftd.cpp
index 3e033e0bb..73fd0017c 100644
--- a/src/core/thread/network_data_leader_ftd.cpp
+++ b/src/core/thread/network_data_leader_ftd.cpp
@@ -284,8 +284,6 @@ exit:
     {
         SendCommissioningSetResponse(aMessage, aMessageInfo, state);
     }
-
-    return;
 }
 
 void Leader::HandleCommissioningGet(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo)
diff --git a/src/ncp/ncp_base.cpp b/src/ncp/ncp_base.cpp
index 991b5e868..d1ec2c643 100644
--- a/src/ncp/ncp_base.cpp
+++ b/src/ncp/ncp_base.cpp
@@ -824,7 +824,6 @@ void NcpBase::UpdateChangedProps(void)
 
 exit:
     mDidInitialUpdates = true;
-    return;
 }
 
 // ----------------------------------------------------------------------------