diff --git a/calcite/pom.xml b/calcite/pom.xml
index 74cad2c3..93daf7db 100644
--- a/calcite/pom.xml
+++ b/calcite/pom.xml
@@ -13,6 +13,8 @@
     <description>Apache Calcite SQL adapter over the Vortex columnar file format (demo: filter/project/aggregate push-down).</description>
 
     <properties>
+        <!-- Calcite pulls in protobuf-java, whose UnsafeUtil calls sun.misc.Unsafe (not ours: we never use Unsafe). -->
+        <test.unsafe.args>--sun-misc-unsafe-memory-access=allow</test.unsafe.args>
         <calcite.version>1.42.0</calcite.version>
     </properties>
 
diff --git a/cli/pom.xml b/cli/pom.xml
index 65c05137..78811a9a 100644
--- a/cli/pom.xml
+++ b/cli/pom.xml
@@ -13,6 +13,8 @@
     <description>Command-line interface for the Vortex columnar file format.</description>
 
     <properties>
+        <!-- PosixTerminal (TUI) calls Linker#downcallHandle, a restricted FFM method. -->
+        <test.native.args>--enable-native-access=ALL-UNNAMED</test.native.args>
     </properties>
 
     <dependencies>
@@ -85,7 +87,7 @@
                          {@code coverage} profile is active; empty default otherwise (set
                          in the root pom). Without it the agent never attaches and the
                          cli module reports 0% coverage. -->
-                    <argLine>@{argLine} --sun-misc-unsafe-memory-access=allow</argLine>
+                    <argLine>@{argLine} --sun-misc-unsafe-memory-access=allow ${test.native.args}</argLine>
                     <includes>
                         <include>**/*Test.java</include>
                         <include>**/*IT.java</include>
diff --git a/parquet/pom.xml b/parquet/pom.xml
index 96e2440d..5c114b6d 100644
--- a/parquet/pom.xml
+++ b/parquet/pom.xml
@@ -12,6 +12,11 @@
     <name>vortex-parquet</name>
     <description>Parquet conversion support for the Vortex columnar file format.</description>
 
+    <properties>
+        <!-- zstd-jni (Parquet page decompression) calls System#loadLibrary, a restricted method. -->
+        <test.native.args>--enable-native-access=ALL-UNNAMED</test.native.args>
+    </properties>
+
     <dependencies>
         <!-- production -->
         <dependency>
diff --git a/pom.xml b/pom.xml
index b4858c68..754475a2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -131,6 +131,11 @@
              run with it so the Vector API kernels are exercised; CI also runs a leg with it empty
              (-Dtest.vector.args=), the configuration users get by default. -->
         <test.vector.args>--add-modules jdk.incubator.vector</test.vector.args>
+        <!-- Per-module opt-ins for the unit-test JVM, empty here so a module that never touches native code or
+             sun.misc.Unsafe runs without them: a module sets the property in its own <properties> only when its
+             tests trip the matching JDK warning (FFM or System.loadLibrary callers; Unsafe users such as protobuf-java). -->
+        <test.native.args />
+        <test.unsafe.args />
         <!-- release plugins -->
         <central-publishing-plugin.version>0.11.0</central-publishing-plugin.version>
         <maven-gpg-plugin.version>3.2.8</maven-gpg-plugin.version>
@@ -391,7 +396,7 @@
                              {@code net.bytebuddy:byte-buddy-agent:jar} is resolved to an absolute path
                              by {@code maven-dependency-plugin:properties} (declared in build/plugins);
                              loading it as a javaagent suppresses the Mockito self-attach warning. -->
-                        <argLine>@{argLine} -javaagent:${net.bytebuddy:byte-buddy-agent:jar} --sun-misc-unsafe-memory-access=allow --enable-native-access=ALL-UNNAMED ${test.vector.args}</argLine>
+                        <argLine>@{argLine} -javaagent:${net.bytebuddy:byte-buddy-agent:jar} ${test.vector.args} ${test.native.args} ${test.unsafe.args}</argLine>
                     </configuration>
                 </plugin>
                 <plugin>
diff --git a/reader/pom.xml b/reader/pom.xml
index c720f4ea..5fe41cb9 100644
--- a/reader/pom.xml
+++ b/reader/pom.xml
@@ -14,6 +14,11 @@
         25+), no JNI, no sun.misc.Unsafe.
     </description>
 
+    <properties>
+        <!-- Our own FFM zstd binding (io.github.dfa1.zstd.NativeLibrary calls SymbolLookup#libraryLookup, a restricted method). -->
+        <test.native.args>--enable-native-access=ALL-UNNAMED</test.native.args>
+    </properties>
+
     <dependencies>
         <!-- production -->
         <dependency>
diff --git a/writer/pom.xml b/writer/pom.xml
index 568cc9a6..486dea74 100644
--- a/writer/pom.xml
+++ b/writer/pom.xml
@@ -14,6 +14,11 @@
         implementation.
     </description>
 
+    <properties>
+        <!-- Our own FFM zstd binding (io.github.dfa1.zstd.NativeLibrary calls SymbolLookup#libraryLookup, a restricted method). -->
+        <test.native.args>--enable-native-access=ALL-UNNAMED</test.native.args>
+    </properties>
+
     <dependencies>
         <!-- production -->
         <dependency>