diff --git a/DDAlign/src/GlobalDetectorAlignment.cpp b/DDAlign/src/GlobalDetectorAlignment.cpp
index fb30c05454b9d7be1b72644b8acd9238eb187257..887f813309513622b77cb44f1603eb9928837da2 100644
--- a/DDAlign/src/GlobalDetectorAlignment.cpp
+++ b/DDAlign/src/GlobalDetectorAlignment.cpp
@@ -24,6 +24,11 @@
 #include "TGeoMatrix.h"
 #include "TGeoManager.h"
 
+
+#ifdef __GNUC__    // Disable some diagnostics.
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 /// Namespace for the AIDA detector description toolkit
 namespace DD4hep {
 
diff --git a/DDDB/src/CondDB2DDDB.cpp b/DDDB/src/CondDB2DDDB.cpp
index aef0101725a33f0d144e8036610364c60c0ffad6..d980df0522bb25fd8acb459f53bdc42cd9aad346 100644
--- a/DDDB/src/CondDB2DDDB.cpp
+++ b/DDDB/src/CondDB2DDDB.cpp
@@ -32,6 +32,10 @@ using namespace std;
 using namespace DD4hep;
 using namespace DD4hep::DDDB;
 
+#ifdef __GNUC__    // Disable some diagnostics.
+#pragma GCC diagnostic ignored "-Wunused-function"
+#endif
+
 /// Namespace for the AIDA detector description toolkit
 namespace DD4hep {
 
diff --git a/DDEve/src/Display.cpp b/DDEve/src/Display.cpp
index 34694ed6473959e67f8d690f3dcbec7daa9ab9af..815531c7b0e3c6bd94de6b52054bd53159086e3d 100644
--- a/DDEve/src/Display.cpp
+++ b/DDEve/src/Display.cpp
@@ -372,7 +372,7 @@ TFile* Display::Open(const char* name) const   {
 }
 
 /// Consumer event data
-void Display::OnFileOpen(EventHandler& handler )   {
+void Display::OnFileOpen(EventHandler& /* handler */ )   {
 }
 
 /// Consumer event data
diff --git a/examples/ClientTests/compact/IronCylinder.xml b/examples/ClientTests/compact/IronCylinder.xml
index 66c5087ef6456815a6ff129f37ecf5fd981dc988..5d87b2c79485e1ee2d05cb2001583ad3f974b40a 100644
--- a/examples/ClientTests/compact/IronCylinder.xml
+++ b/examples/ClientTests/compact/IronCylinder.xml
@@ -62,7 +62,6 @@
   <readouts>
     <readout name="HcalBarrelHits">
       <id>system:8,barrel:3,module:7,layer:5,slice:10,eta:10,phi:5</id> 
-      <segmentation type="GridPhiEta"  grid_size_eta="0.1*cm" phi_bins="10" />
     </readout>
     <readout name="ContainmentHits">
       <id>system:8,barrel:3</id>