diff --git a/src/plugin/Manager.cc b/src/plugin/Manager.cc
index 12884fdc6b..4d427a1ddf 100644
--- a/src/plugin/Manager.cc
+++ b/src/plugin/Manager.cc
@@ -112,10 +112,10 @@ void Manager::SearchDynamicPlugins(const std::string& dir)
 		if ( name.empty() )
 			reporter->FatalError("empty plugin magic file %s", magic.c_str());
 
-		if ( dynamic_plugins.find(lower_name) != dynamic_plugins.end() )
+		if ( const auto& other = dynamic_plugins.find(lower_name); other != dynamic_plugins.end() )
 			{
-			DBG_LOG(DBG_PLUGINS, "Found already known plugin %s in %s, ignoring", name.c_str(),
-			        dir.c_str());
+			reporter->Warning("ignoring dynamic plugin %s from %s, already found in %s",
+			                  name.c_str(), dir.c_str(), other->second.c_str());
 			return;
 			}
 
diff --git a/testing/btest/Baseline/plugins.duplicate-pktsrc/output b/testing/btest/Baseline/plugins.duplicate-pktsrc/output
new file mode 100644
index 0000000000..19f5d4978e
--- /dev/null
+++ b/testing/btest/Baseline/plugins.duplicate-pktsrc/output
@@ -0,0 +1,5 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+warning in <...>/init-bare.zeek, line 1: ignoring dynamic plugin Demo::Foo from <...>/build, already found in <...>/build_backup
+Demo::Foo - A Foo packet source (dynamic, version 1.0.0)
+    [Packet Source] FooPktSrc (interface prefix "foo"; supports live and trace input)
+
diff --git a/testing/btest/plugins/duplicate-pktsrc.zeek b/testing/btest/plugins/duplicate-pktsrc.zeek
new file mode 100644
index 0000000000..aecc6190c6
--- /dev/null
+++ b/testing/btest/plugins/duplicate-pktsrc.zeek
@@ -0,0 +1,8 @@
+# @TEST-DOC: Loading two plugins with the same name triggers a warning.
+
+# @TEST-EXEC: ${DIST}/auxil/zeek-aux/plugin-support/init-plugin -u . Demo Foo
+# @TEST-EXEC: cp -r %DIR/pktsrc-plugin/* .
+# @TEST-EXEC: ./configure --zeek-dist=${DIST} && make
+# @TEST-EXEC: cp -R build build_backup
+# @TEST-EXEC: ZEEK_PLUGIN_PATH=`pwd`/build_backup:`pwd`/build zeek -NN Demo::Foo  >output 2>&1
+# @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff output