diff --git a/src/Dict.h b/src/Dict.h
index 842ed53eea..d33e6d597b 100644
--- a/src/Dict.h
+++ b/src/Dict.h
@@ -645,7 +645,7 @@ public:
 			auto loc = detail::GetCurrentLocation();
 			reporter->RuntimeError(&loc,
 			                       "Attempted to create DictEntry with excessively large key, "
-			                       "truncating key (%" PRIu64 " > %d)",
+			                       "truncating key (%" PRIu64 " > %u)",
 			                       key_size, detail::DictEntry<T>::MAX_KEY_SIZE);
 			}
 
diff --git a/src/RandTest.cc b/src/RandTest.cc
index 554e9db2c5..7870c4fb6a 100644
--- a/src/RandTest.cc
+++ b/src/RandTest.cc
@@ -79,7 +79,6 @@ void RandTest::add(const void* buf, int bufl)
 		if ( sccfirst )
 			{
 			sccfirst = 0;
-			scclast = 0;
 			sccu0 = oc;
 			}
 		else
@@ -98,17 +97,15 @@ void RandTest::end(double* r_ent, double* r_chisq, double* r_mean, double* r_mon
                    double* r_scc)
 	{
 	int i;
-	double ent, chisq, scc, datasum;
-	ent = 0.0;
-	chisq = 0.0;
-	scc = 0.0;
-	datasum = 0.0;
+	double ent = 0.0;
+	double chisq = 0.0;
+	double datasum = 0.0;
 	double prob[256]; /* Probabilities per bin for entropy */
 
 	/* Complete calculation of serial correlation coefficient */
 	scct1 = scct1 + scclast * sccu0;
 	scct2 = scct2 * scct2;
-	scc = totalc * scct3 - scct2;
+	double scc = totalc * scct3 - scct2;
 	if ( scc == 0.0 )
 		scc = -100000;
 	else
diff --git a/src/ZeekString.cc b/src/ZeekString.cc
index 2e4fc2b23f..860d444de1 100644
--- a/src/ZeekString.cc
+++ b/src/ZeekString.cc
@@ -77,6 +77,9 @@ void String::Reset()
 
 const String& String::operator=(const String& bs)
 	{
+	if ( this == &bs )
+		return *this;
+
 	Reset();
 	n = bs.n;
 	b = new u_char[n + 1];
diff --git a/src/plugin/Manager.cc b/src/plugin/Manager.cc
index 8e925ef493..f7962945fe 100644
--- a/src/plugin/Manager.cc
+++ b/src/plugin/Manager.cc
@@ -630,7 +630,7 @@ Plugin* Manager::LookupPluginByPath(std::string_view _path)
 static bool hook_cmp(std::pair<int, Plugin*> a, std::pair<int, Plugin*> b)
 	{
 	if ( a.first == b.first )
-		return util::strtolower(a.second->Name()) < util::strtolower(a.second->Name());
+		return util::strtolower(a.second->Name()) < util::strtolower(b.second->Name());
 
 	// Reverse sort.
 	return a.first > b.first;
diff --git a/src/probabilistic/BloomFilter.cc b/src/probabilistic/BloomFilter.cc
index 56dc10603c..b637fed68c 100644
--- a/src/probabilistic/BloomFilter.cc
+++ b/src/probabilistic/BloomFilter.cc
@@ -70,6 +70,10 @@ std::unique_ptr<BloomFilter> BloomFilter::Unserialize(const broker::data& data)
 		case Counting:
 			bf = std::unique_ptr<BloomFilter>(new CountingBloomFilter());
 			break;
+
+		default:
+			reporter->Error("found invalid bloom filter type");
+			return nullptr;
 		}
 
 	if ( ! bf->DoUnserialize((*v)[2]) )
diff --git a/src/probabilistic/CardinalityCounter.cc b/src/probabilistic/CardinalityCounter.cc
index 72168cd4e0..c6de5c6581 100644
--- a/src/probabilistic/CardinalityCounter.cc
+++ b/src/probabilistic/CardinalityCounter.cc
@@ -158,7 +158,7 @@ double CardinalityCounter::Size() const
 	answer = 1 / answer;
 	answer = (alpha_m * m * m * answer);
 
-	if ( answer <= 5.0 * (m / 2) )
+	if ( answer <= 5.0 * (((double)m) / 2) )
 		return m * log(((double)m) / V);
 
 	else if ( answer <= (pow(2, 64) / 30) )
diff --git a/src/util.cc b/src/util.cc
index ae3a9d12b7..f19e1c0ba0 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -349,7 +349,7 @@ static bool read_random_seeds(const char* read_file, uint32_t* seed,
 	// Read seeds for hmac-md5/siphash/highwayhash.
 	for ( auto& v : buf )
 		{
-		int tmp;
+		uint32_t tmp;
 		if ( fscanf(f, "%u", &tmp) != 1 )
 			{
 			fclose(f);