diff --git a/lib/diameter/test/diameter_capx_SUITE.erl b/lib/diameter/test/diameter_capx_SUITE.erl
index e6b1558bf69e..88b798d563f0 100644
--- a/lib/diameter/test/diameter_capx_SUITE.erl
+++ b/lib/diameter/test/diameter_capx_SUITE.erl
@@ -312,7 +312,7 @@ server_closed(Config, F, RC) ->
     end.
 
 %% server_reject/3
-    
+
 server_reject(Config, F, RC) ->
     true = diameter:subscribe(?SERVER),
     OH = host(Config),
@@ -345,7 +345,7 @@ client_closed(Config, Host, F, RC) ->
 
 %% client_recv/1
 
-client_recv(CRef) ->    
+client_recv(CRef) ->
     receive
         ?event{service = ?CLIENT,
                info = {closed, CRef, Reason, {connect, _}}} ->
diff --git a/lib/diameter/test/diameter_failover_SUITE.erl b/lib/diameter/test/diameter_failover_SUITE.erl
index 429b6328e6ce..53398dd93e94 100644
--- a/lib/diameter/test/diameter_failover_SUITE.erl
+++ b/lib/diameter/test/diameter_failover_SUITE.erl
@@ -174,7 +174,7 @@ realm(Host) ->
 
 call(Req, Opts) ->
     diameter:call(?CLIENT, ?APP_ALIAS, Req, Opts).
-    
+
 set([H|T], Vs) ->
     [H | Vs ++ T].
 
diff --git a/lib/diameter/test/diameter_relay_SUITE.erl b/lib/diameter/test/diameter_relay_SUITE.erl
index c0351f8cf2fd..32b30d3cca73 100644
--- a/lib/diameter/test/diameter_relay_SUITE.erl
+++ b/lib/diameter/test/diameter_relay_SUITE.erl
@@ -248,7 +248,7 @@ call(Server) ->
 
 call(Req, Opts) ->
     diameter:call(?CLIENT, ?APP_ALIAS, Req, Opts).
-    
+
 set([H|T], Vs) ->
     [H | Vs ++ T].
 
diff --git a/lib/diameter/test/diameter_traffic_SUITE.erl b/lib/diameter/test/diameter_traffic_SUITE.erl
index 78131b4ec4c6..bc5ca416c2c3 100644
--- a/lib/diameter/test/diameter_traffic_SUITE.erl
+++ b/lib/diameter/test/diameter_traffic_SUITE.erl
@@ -516,10 +516,10 @@ send_multiple_filters(Config, Fs) ->
 %% Ensure that we can pass a request in any form to diameter:call/4,
 %% only the return value from the prepare_request callback being
 %% significant.
-send_anything(Config) ->    
+send_anything(Config) ->
     #diameter_base_STA{'Result-Code' = ?SUCCESS}
         = call(Config, anything).
-    
+
 %% ===========================================================================
 
 call(Config, Req) ->
diff --git a/lib/diameter/test/diameter_util.erl b/lib/diameter/test/diameter_util.erl
index 6b1dc1f0c97a..0c42f955ad18 100644
--- a/lib/diameter/test/diameter_util.erl
+++ b/lib/diameter/test/diameter_util.erl
@@ -212,7 +212,7 @@ read_priv(Config, Name) ->
 read(Path) ->
     {ok, Bin} = file:read_file(Path),
     binary_to_term(Bin).
-    
+
 %% map_priv/3
 %%
 %% Modify a term in a file and return both old and new values.