diff --git a/modules/core/02-client/types/keys.go b/modules/core/02-client/types/keys.go
index 74597232d7c..919f91f9ebe 100644
--- a/modules/core/02-client/types/keys.go
+++ b/modules/core/02-client/types/keys.go
@@ -34,7 +34,9 @@ func FormatClientIdentifier(clientType string, sequence uint64) string {
 
 // IsClientIDFormat checks if a clientID is in the format required on the SDK for
 // parsing client identifiers. The client identifier must be in the form: `{client-type}-{N}
-var IsClientIDFormat = regexp.MustCompile(`^.*[^\n-]-[0-9]{1,20}$`).MatchString
+// which per the specification only permits ASCII for the {client-type} segment and
+// 1 to 20 digits for the {N} segment.
+var IsClientIDFormat = regexp.MustCompile(`^\w+([\w-]+\w)?-[0-9]{1,20}$`).MatchString
 
 // IsValidClientID checks if the clientID is valid and can be parsed into the client
 // identifier format.
diff --git a/modules/core/02-client/types/keys_test.go b/modules/core/02-client/types/keys_test.go
index f0e5fcd02b7..0da1b4c3e4b 100644
--- a/modules/core/02-client/types/keys_test.go
+++ b/modules/core/02-client/types/keys_test.go
@@ -35,22 +35,31 @@ func TestParseClientIdentifier(t *testing.T) {
 		{"negative sequence", "tendermint--1", "tendermint", 0, false},
 		{"invalid format", "tendermint-tm", "tendermint", 0, false},
 		{"empty clientype", " -100", "tendermint", 0, false},
+		{"with in the middle tabs", "a\t\t\t-100", "tendermint", 0, false},
+		{"leading tabs", "\t\t\ta-100", "tendermint", 0, false},
+		{"with whitespace", "                  a-100", "tendermint", 0, false},
+		{"leading hyphens", "-----a-100", "tendermint", 0, false},
+		{"with slash", "tendermint/-100", "tendermint", 0, false},
+		{"non-ASCII:: emoji", "🚨😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎😎-100", "tendermint", 0, false},
+		{"non-ASCII:: others", "世界-100", "tendermint", 0, false},
 	}
 
 	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			clientType, seq, err := types.ParseClientIdentifier(tc.clientID)
+			valid := types.IsValidClientID(tc.clientID)
+			require.Equal(t, tc.expSeq, seq, tc.clientID)
 
-		clientType, seq, err := types.ParseClientIdentifier(tc.clientID)
-		valid := types.IsValidClientID(tc.clientID)
-		require.Equal(t, tc.expSeq, seq, tc.clientID)
-
-		if tc.expPass {
-			require.NoError(t, err, tc.name)
-			require.True(t, valid)
-			require.Equal(t, tc.clientType, clientType)
-		} else {
-			require.Error(t, err, tc.name, tc.clientID)
-			require.False(t, valid)
-			require.Equal(t, "", clientType)
-		}
+			if tc.expPass {
+				require.NoError(t, err, tc.name)
+				require.True(t, valid)
+				require.Equal(t, tc.clientType, clientType)
+			} else {
+				require.Error(t, err, tc.name, tc.clientID)
+				require.False(t, valid)
+				require.Equal(t, "", clientType)
+			}
+		})
 	}
 }