diff --git a/llvm/test/tools/llvm-exegesis/X86/dummy-perf-counters-subprocess.s b/llvm/test/tools/llvm-exegesis/X86/dummy-perf-counters-subprocess.s
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-exegesis/X86/dummy-perf-counters-subprocess.s
@@ -0,0 +1,7 @@
+# REQUIRES: exegesis-can-measure-latency, x86_64-linux
+
+# RUN: not llvm-exegesis -mtriple=x86_64-unknown-unknown -mode=latency -snippets-file=%s -execution-mode=subprocess -use-dummy-perf-counters 2>&1 | FileCheck %s
+
+# CHECK: llvm-exegesis error: Dummy perf counters are not supported in the subprocess execution mode.
+
+mov $0, %rax
diff --git a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
--- a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
+++ b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
@@ -477,6 +477,11 @@
   if (BenchmarkPhaseSelector == BenchmarkPhaseSelectorE::Measure)
     ExitOnErr(State.getExegesisTarget().checkFeatureSupport());
 
+  if (ExecutionMode == BenchmarkRunner::ExecutionModeE::SubProcess &&
+      UseDummyPerfCounters)
+    ExitWithError("Dummy perf counters are not supported in the subprocess "
+                  "execution mode.");
+
   const std::unique_ptr<BenchmarkRunner> Runner =
       ExitOnErr(State.getExegesisTarget().createBenchmarkRunner(
           BenchmarkMode, State, BenchmarkPhaseSelector, ExecutionMode,