diff --git a/CommonLibs/ConfigurationTest.cpp b/CommonLibs/ConfigurationTest.cpp
index a21ea86..3a2045f 100644
--- a/CommonLibs/ConfigurationTest.cpp
+++ b/CommonLibs/ConfigurationTest.cpp
@@ -46,7 +46,7 @@
 
 	gConfig.setUpdateHook(purgeConfig);
 
-	char *keys[5] = {"key1", "key2", "key3", "key4", "key5"};
+	const char *keys[5] = {"key1", "key2", "key3", "key4", "key5"};
 
 	for (int i=0; i<5; i++) {
 		gConfig.set(keys[i],i);
diff --git a/CommonLibs/URLEncode.cpp b/CommonLibs/URLEncode.cpp
index 870db33..025ef60 100644
--- a/CommonLibs/URLEncode.cpp
+++ b/CommonLibs/URLEncode.cpp
@@ -35,7 +35,7 @@
 {
 	static const char *digits = "01234567890ABCDEF";
 	string retVal="";
-	for (int i=0; i<c.length(); i++)
+	for (size_t i=0; i<c.length(); i++)
 	{
 		const char ch = c[i];
 		if (isalnum(ch) || strchr("-_.!~'()",ch)) {
diff --git a/Transceiver52M/DummyLoad.cpp b/Transceiver52M/DummyLoad.cpp
index d11226e..38718a0 100644
--- a/Transceiver52M/DummyLoad.cpp
+++ b/Transceiver52M/DummyLoad.cpp
@@ -97,11 +97,11 @@
   underrunLock.unlock();
   if (currstamp+len < timestamp) {
 	usleep(100); 
-	return NULL;
+	return 0;
   } 
   else if (currstamp < timestamp) {
 	usleep(100);
-	return NULL;
+	return 0;
   }
   else if (timestamp+len < currstamp) {
 	memcpy(buf,dummyBurst+dummyBurstCursor*2,sizeof(short)*2*(dummyBurstSz-dummyBurstCursor));