diff --git a/slsDetectorSoftware/src/Detector.cpp b/slsDetectorSoftware/src/Detector.cpp
index 19db54e9a..80b3e3fb3 100644
--- a/slsDetectorSoftware/src/Detector.cpp
+++ b/slsDetectorSoftware/src/Detector.cpp
@@ -1244,6 +1244,9 @@ Result<std::string> Detector::getFileNamePrefix(Positions pos) const {
 }
 
 void Detector::setFileNamePrefix(const std::string &fname, Positions pos) {
+    if (fname.find_first_of("/ ") != std::string::npos) {
+        throw RuntimeError("Cannot set file name prefix with '/' or ' '");
+    }
     pimpl->Parallel(&Module::setFileName, pos, fname);
 }
 
diff --git a/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp b/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp
index 627bbe4d1..34d433591 100644
--- a/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp
+++ b/slsDetectorSoftware/tests/test-CmdProxy-rx.cpp
@@ -572,6 +572,9 @@ TEST_CASE("fname", "[.cmd]") {
         proxy.Call("fname", {"run"}, -1, PUT, oss);
         REQUIRE(oss.str() == "fname run\n");
     }
+    REQUIRE_THROWS(proxy.Call("fname", {"fdf/dfd"}, -1, PUT));
+    REQUIRE_THROWS(proxy.Call("fname", {"fdf dfd"}, -1, PUT));
+    
     for (int i = 0; i != det.size(); ++i) {
         det.setFileNamePrefix(prev_val[i], {i});
     }