diff --git a/NEWS b/NEWS
index ff3c5be3dc..eb0ee24ea6 100644
--- a/NEWS
+++ b/NEWS
@@ -71,6 +71,13 @@ Changed Functionality
   now timeout after 5 minutes by default instead of no timeout, and extracted
   files now have a default size limit of 100MB instead of unlimited.
 
+- If a Spicy protocol analyzers feeds data into file analysis, it now
+  needs to call Zeek's `Files::register_protocol()` and provide a
+  callback for computing file handles. If that's missing, Zeek will
+  issue a warning. While this was not necessary in previous versions,
+  it aligns with the same requirement for traditional analyzers and
+  enables customizing file handles for protocol-specific semantics.
+
 Removed Functionality
 ---------------------
 
diff --git a/src/file_analysis/Manager.h b/src/file_analysis/Manager.h
index 327e5b2cd3..bdc850b171 100644
--- a/src/file_analysis/Manager.h
+++ b/src/file_analysis/Manager.h
@@ -351,6 +351,19 @@ public:
      */
     std::string DetectMIME(const u_char* data, uint64_t len) const;
 
+    /**
+     * Sets #current_file_id to a hash of a unique file handle string based on
+     * what the \c get_file_handle event derives from the connection params.
+     * Event queue is flushed so that we can get the handle value immediately.
+     * @param tag network protocol over which the file is transferred.
+     * @param conn network connection over which the file is transferred.
+     * @param is_orig true if the file is being sent from connection originator
+     *        or false if is being sent in the opposite direction.
+     * @return #current_file_id, which is a hash of a unique file handle string
+     *         set by a \c get_file_handle event handler.
+     */
+    std::string GetFileID(const zeek::Tag& tag, Connection* c, bool is_orig);
+
     uint64_t CurrentFiles() { return id_map.size(); }
 
     uint64_t MaxFiles() { return max_files; }
@@ -399,19 +412,6 @@ protected:
      */
     bool RemoveFile(const std::string& file_id);
 
-    /**
-     * Sets #current_file_id to a hash of a unique file handle string based on
-     * what the \c get_file_handle event derives from the connection params.
-     * Event queue is flushed so that we can get the handle value immediately.
-     * @param tag network protocol over which the file is transferred.
-     * @param conn network connection over which the file is transferred.
-     * @param is_orig true if the file is being sent from connection originator
-     *        or false if is being sent in the opposite direction.
-     * @return #current_file_id, which is a hash of a unique file handle string
-     *         set by a \c get_file_handle event handler.
-     */
-    std::string GetFileID(const zeek::Tag& tag, Connection* c, bool is_orig);
-
     /**
      * Check if analysis is available for files transferred over a given
      * network protocol.
diff --git a/src/spicy/runtime-support.cc b/src/spicy/runtime-support.cc
index 0319ba15ee..e6b340e0be 100644
--- a/src/spicy/runtime-support.cc
+++ b/src/spicy/runtime-support.cc
@@ -689,8 +689,22 @@ rt::cookie::FileState* rt::cookie::FileStateStack::push(std::optional<std::strin
     std::string fid;
     if ( fid_provided )
         fid = *fid_provided;
-    else
-        fid = file_mgr->HashHandle(hilti::rt::fmt("%s.%d", _analyzer_id, ++_id_counter));
+    else {
+        auto cookie = static_cast<Cookie*>(hilti::rt::context::cookie());
+        assert(cookie);
+
+        if ( auto c = cookie->protocol ) {
+            auto tag = spicy_mgr->tagForProtocolAnalyzer(c->analyzer->GetAnalyzerTag());
+            fid = file_mgr->GetFileID(tag, c->analyzer->Conn(), c->is_orig);
+        }
+
+        if ( fid.empty() )
+            // If we can't get a FID from the file manager (e.g., because don't
+            // have a current protocol), we make one up.
+            fid = file_mgr->HashHandle(hilti::rt::fmt("%s.%d", _analyzer_id, ++_id_counter));
+    }
+
+    assert(! fid.empty());
     _stack.emplace_back(std::move(fid));
     return &_stack.back();
 }
diff --git a/testing/btest/Baseline/spicy.file-analysis-data-in/output-1 b/testing/btest/Baseline/spicy.file-analysis-data-in/output-1
index 8a97453dba..afec41f20e 100644
--- a/testing/btest/Baseline/spicy.file-analysis-data-in/output-1
+++ b/testing/btest/Baseline/spicy.file-analysis-data-in/output-1
@@ -1,3 +1,5 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-FM47gX3vI5ofQPm1li
-FZjUS57tUkGFTibv3
+FU6P513gQKLVP6iwmf
+FU6P513gQKLVP6iwmf
+get_file_handle called
+get_file_handle called
diff --git a/testing/btest/Baseline/spicy.file-data-in-at-offset/output b/testing/btest/Baseline/spicy.file-data-in-at-offset/output
index 8a97453dba..90a64302f0 100644
--- a/testing/btest/Baseline/spicy.file-data-in-at-offset/output
+++ b/testing/btest/Baseline/spicy.file-data-in-at-offset/output
@@ -1,3 +1,3 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-FM47gX3vI5ofQPm1li
-FZjUS57tUkGFTibv3
+FU6P513gQKLVP6iwmf
+FU6P513gQKLVP6iwmf
diff --git a/testing/btest/spicy/file-analysis-data-in-concurrent.zeek b/testing/btest/spicy/file-analysis-data-in-concurrent.zeek
index fe8c8c3afe..3a42662615 100644
--- a/testing/btest/spicy/file-analysis-data-in-concurrent.zeek
+++ b/testing/btest/spicy/file-analysis-data-in-concurrent.zeek
@@ -1,12 +1,23 @@
 # @TEST-REQUIRES: have-spicy
 #
 # @TEST-EXEC: spicyz -d -o test.hlto ssh.spicy ./ssh-cond.evt
-# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T >output
+# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T >output 2>&1
 # @TEST-EXEC: btest-diff output
 
-event zeek_init() {
-    Analyzer::register_for_port(Analyzer::ANALYZER_SPICY_SSH, 22/tcp);
-}
+module SSH;
+
+global i: count = 0;
+
+function get_file_handle(c: connection, is_orig: bool): string
+	{
+	return cat(c$uid, ++i);
+	}
+
+event zeek_init()
+	{
+	Analyzer::register_for_port(Analyzer::ANALYZER_SPICY_SSH, 22/tcp);
+	Files::register_protocol(Analyzer::ANALYZER_SSH, [$get_file_handle=SSH::get_file_handle]); # use tag of replaced analyzer
+	}
 
 # @TEST-START-FILE ssh.spicy
 module SSH;
diff --git a/testing/btest/spicy/file-analysis-data-in.zeek b/testing/btest/spicy/file-analysis-data-in.zeek
index 4418eabe94..de8a5c079a 100644
--- a/testing/btest/spicy/file-analysis-data-in.zeek
+++ b/testing/btest/spicy/file-analysis-data-in.zeek
@@ -2,7 +2,7 @@
 #
 # @TEST-EXEC: cat ssh.spicy ssh-1.spicy > ssh-test.spicy
 # @TEST-EXEC: spicyz -d -o test.hlto ssh-test.spicy ./ssh-cond.evt
-# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T | sort  >output-1
+# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T 2>&1 | sort  >output-1
 #
 # @TEST-EXEC: cat x509.log | grep -v ^# | cut -f 4-5 >x509.log.tmp && mv x509.log.tmp x509.log
 # @TEST-EXEC: btest-diff x509.log
@@ -12,7 +12,7 @@
 #
 # @TEST-EXEC: cat ssh.spicy ssh-2.spicy > ssh-test.spicy
 # @TEST-EXEC: spicyz -d -o test.hlto ssh-test.spicy ./ssh-cond.evt
-# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T | sort  >output-2
+# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T 2>&1  | sort  >output-2
 #
 # @TEST-EXEC: cat files.log | zeek-cut fuid filename >files.log.tmp && mv files.log.tmp files-2.log
 # @TEST-EXEC: btest-diff files-2.log
@@ -20,9 +20,19 @@
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=diff-canonifier-spicy btest-diff output-1
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=diff-canonifier-spicy btest-diff output-2
 
-event zeek_init() {
-    Analyzer::register_for_port(Analyzer::ANALYZER_SPICY_SSH, 22/tcp);
-}
+module SSH;
+
+function get_file_handle(c: connection, is_orig: bool): string
+	{
+	print "get_file_handle called";
+	return cat(c$uid);
+	}
+
+event zeek_init()
+	{
+	Analyzer::register_for_port(Analyzer::ANALYZER_SPICY_SSH, 22/tcp);
+	Files::register_protocol(Analyzer::ANALYZER_SSH, [$get_file_handle=SSH::get_file_handle]); # use tag of replaced analyzer
+	}
 
 # @TEST-START-FILE ssh.spicy
 module SSH;
diff --git a/testing/btest/spicy/file-data-in-at-offset.zeek b/testing/btest/spicy/file-data-in-at-offset.zeek
index e2b680f37f..9f06933a1c 100644
--- a/testing/btest/spicy/file-data-in-at-offset.zeek
+++ b/testing/btest/spicy/file-data-in-at-offset.zeek
@@ -1,15 +1,25 @@
 # @TEST-REQUIRES: have-spicy
 #
 # @TEST-EXEC: spicyz -d -o test.hlto ssh.spicy ./ssh-cond.evt
-# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T | sort  >output
+# @TEST-EXEC: zeek -r ${TRACES}/ssh/single-conn.trace test.hlto %INPUT Spicy::enable_print=T 2>&1 | sort  >output
 #
 # @TEST-EXEC: cat x509.log | grep -v ^# | cut -f 4-5 >x509.log.tmp && mv x509.log.tmp x509.log
 # @TEST-EXEC: btest-diff x509.log
 # @TEST-EXEC: btest-diff output
 
-event zeek_init() {
-    Analyzer::register_for_port(Analyzer::ANALYZER_SPICY_SSH, 22/tcp);
-}
+module SSH;
+
+function get_file_handle(c: connection, is_orig: bool): string
+	{
+	return cat(c$uid);
+	}
+
+event zeek_init()
+	{
+	Analyzer::register_for_port(Analyzer::ANALYZER_SPICY_SSH, 22/tcp);
+	Files::register_protocol(Analyzer::ANALYZER_SSH, [$get_file_handle=SSH::get_file_handle]); # use tag of replaced analyzer
+
+	}
 
 # @TEST-START-FILE ssh.spicy
 module SSH;