diff --git a/src/cli/cli_coap.cpp b/src/cli/cli_coap.cpp
index 58e1cfe52..f4ecdc244 100644
--- a/src/cli/cli_coap.cpp
+++ b/src/cli/cli_coap.cpp
@@ -43,6 +43,12 @@
 namespace ot {
 namespace Cli {
 
+Coap::Coap(Interpreter &aInterpreter):
+    mInterpreter(aInterpreter)
+{
+    memset(&mResource, 0, sizeof(mResource));
+}
+
 void Coap::PrintPayload(otMessage *aMessage) const
 {
     uint8_t buf[kMaxBufferSize];
diff --git a/src/cli/cli_coap.hpp b/src/cli/cli_coap.hpp
index 82a1dc37d..db09f0f58 100644
--- a/src/cli/cli_coap.hpp
+++ b/src/cli/cli_coap.hpp
@@ -60,7 +60,7 @@ public:
      * @param[in]  aInterpreter  The CLI interpreter.
      *
      */
-    Coap(Interpreter &aInterpreter): mInterpreter(aInterpreter) { }
+    Coap(Interpreter &aInterpreter);
 
     /**
      * This method interprets a list of CLI arguments.
diff --git a/src/cli/cli_udp_example.cpp b/src/cli/cli_udp_example.cpp
index cc5ab205c..7e16b56ce 100644
--- a/src/cli/cli_udp_example.cpp
+++ b/src/cli/cli_udp_example.cpp
@@ -54,6 +54,12 @@ const struct UdpExample::Command UdpExample::sCommands[] =
     { "send", &UdpExample::ProcessSend }
 };
 
+UdpExample::UdpExample(Interpreter &aInterpreter):
+    mInterpreter(aInterpreter)
+{
+    memset(&mSocket, 0, sizeof(mSocket));
+}
+
 otError UdpExample::ProcessHelp(int argc, char *argv[])
 {
     for (unsigned int i = 0; i < sizeof(sCommands) / sizeof(sCommands[0]); i++)
diff --git a/src/cli/cli_udp_example.hpp b/src/cli/cli_udp_example.hpp
index fff0e91d7..12a3614a8 100644
--- a/src/cli/cli_udp_example.hpp
+++ b/src/cli/cli_udp_example.hpp
@@ -57,7 +57,7 @@ public:
      * @param[in]  aInterpreter  The CLI interpreter.
      *
      */
-    UdpExample(Interpreter &aInterpreter): mInterpreter(aInterpreter) { }
+    UdpExample(Interpreter &aInterpreter);
 
     /**
      * This method interprets a list of CLI arguments.