diff --git a/Ghidra/Features/Decompiler/src/decompile/cpp/test.cc b/Ghidra/Features/Decompiler/src/decompile/cpp/test.cc
index e81f2564aa..2c19c01741 100644
--- a/Ghidra/Features/Decompiler/src/decompile/cpp/test.cc
+++ b/Ghidra/Features/Decompiler/src/decompile/cpp/test.cc
@@ -14,6 +14,9 @@
  * limitations under the License.
  */
 #include "test.hh"
+
+#include <algorithm>
+
 #include "libdecomp.hh"
 
 vector<UnitTest *> UnitTest::tests;
@@ -21,7 +24,8 @@ vector<UnitTest *> UnitTest::tests;
 /// Run all the tests unless a non-empty set of names is passed in.
 /// In which case, only the named tests in the set are run.
 /// \param testNames is the set of names
-void UnitTest::run(set<string> &testNames)
+/// \return number of failed tests
+int UnitTest::run(set<string> &testNames)
 
 {
   int total = 0;
@@ -42,6 +46,7 @@ void UnitTest::run(set<string> &testNames)
   }
   std::cerr << "==============================" << std::endl;
   std::cerr << passed << "/" << total << " tests passed." << std::endl;
+  return total - passed;
 }
 
 /// Create list of the absolute path of all tests to be run
@@ -75,6 +80,24 @@ void gatherDataTests(const string &dirname,set<string> &testNames,vector<string>
   }
 }
 
+/// \brief This function performs a saturating add on two numbers where the
+/// result is to be used as an exit code for a CLI application.
+///
+/// \param current The current return code
+/// \param add A number to add to the current return code
+/// \return A number that can be used as an exit code up to 255.
+int add_exit_code(int current, int add) {
+  const int CLAMP = 255;
+  int ret = current + add;
+  if (current < 0 ||  	// Sanity checks
+      current > CLAMP ||
+      ret < current ||	// Can only happen due to overflow
+      ret > CLAMP) {  	// Check clamp value
+    ret = CLAMP;	// Set to max exit code
+  }
+  return ret;
+}
+
 int main(int argc, char **argv) {
   bool runUnitTests = true;
   bool runDataTests = true;
@@ -85,7 +108,7 @@ int main(int argc, char **argv) {
   set<string> dataTestNames;
   string dirname("../datatests");
   string sleighdirname("../../../../../../..");
-  if (argc > 0) {
+  while (argc > 0) {
     string command(argv[0]);
     if (command == "-path") {
       dirname = argv[1];
@@ -109,30 +132,39 @@ int main(int argc, char **argv) {
       argv += 1;
       argc -= 1;
     }
-  }
-  if (argc > 0) {
-    string command(argv[0]);
-    if (command == "unittests") {
+    else if (command == "unittests") {
       runUnitTests = true;
       runDataTests = false;	// Run only unit tests
       unitTestNames.insert(argv + 1,argv + argc);
+      break;
     }
     else if (command == "datatests") {
       runUnitTests = false;	// Run only data-tests
       runDataTests = true;
       dataTestNames.insert(argv + 1,argv + argc);
+      break;
     }
     else {
-      cout << "USAGE: ghidra_test [-path <datatestdir>] [[unittests|datatests] [testname1 testname2 ...]]" << endl;
+      cout << "USAGE: ghidra_test [-usesleighenv] [-sleighpath <sleighdir>] [-path <datatestdir>] [[unittests|datatests] [testname1 testname2 ...]]" << endl;
+      return -1;
     }
   }
   startDecompilerLibrary(sleighdirname.c_str());
-  if (runUnitTests)
-    UnitTest::run(unitTestNames);
+
+  // Keep track of failed tests as return code to indicate failures, clamped at
+  // max exit code value in add_exit_code
+  int failedTests = 0;
+  if (runUnitTests) {
+    int errors = UnitTest::run(unitTestNames);
+    failedTests = add_exit_code(failedTests, errors);
+  }
   if (runDataTests) {
     vector<string> testFiles;
     gatherDataTests(dirname,dataTestNames,testFiles);
     cout << endl << endl;
-    FunctionTestCollection::runTestFiles(testFiles,cout);
+    int errors = FunctionTestCollection::runTestFiles(testFiles,cout);
+    failedTests = add_exit_code(failedTests, errors);
   }
+
+  return failedTests;
 }
diff --git a/Ghidra/Features/Decompiler/src/decompile/cpp/test.hh b/Ghidra/Features/Decompiler/src/decompile/cpp/test.hh
index 8b762c5b19..a138f511d0 100644
--- a/Ghidra/Features/Decompiler/src/decompile/cpp/test.hh
+++ b/Ghidra/Features/Decompiler/src/decompile/cpp/test.hh
@@ -54,7 +54,7 @@ struct UnitTest {
     tests.push_back(this);
   }
 
-  static void run(std::set<std::string> &testNames);	///< Run all the instantiated tests
+  static int run(std::set<std::string> &testNames);	///< Run all the instantiated tests
 };
 
 
diff --git a/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.cc b/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.cc
index 66f8d3fa2e..c136a964b0 100644
--- a/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.cc
+++ b/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.cc
@@ -304,7 +304,7 @@ void FunctionTestCollection::runTests(list<string> &lateStream)
 /// Run through all XML files in the given list, processing each in turn.
 /// \param testFiles is the given list of test files
 /// \param s is the output stream to print results to
-void FunctionTestCollection::runTestFiles(const vector<string> &testFiles,ostream &s)
+int FunctionTestCollection::runTestFiles(const vector<string> &testFiles,ostream &s)
 
 {
   int4 totalTestsApplied = 0;
@@ -344,4 +344,5 @@ void FunctionTestCollection::runTestFiles(const vector<string> &testFiles,ostrea
       if (iter == failures.end()) break;
     }
   }
+  return totalTestsApplied - totalTestsSucceeded;
 }
diff --git a/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.hh b/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.hh
index 52125b4018..46abd6bce8 100644
--- a/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.hh
+++ b/Ghidra/Features/Decompiler/src/decompile/cpp/testfunction.hh
@@ -91,7 +91,7 @@ public:
   void restoreXml(DocumentStorage &store,const Element *el);	///< Load tests from a \<decompilertest> tag.
   void restoreXmlOldForm(DocumentStorage &store,const Element *el);	///< Load tests from \<binaryimage> tag.
   void runTests(list<string> &lateStream);	///< Run the script and perform the tests
-  static void runTestFiles(const vector<string> &testFiles,ostream &s);	///< Run tests for each listed file
+  static int runTestFiles(const vector<string> &testFiles,ostream &s);	///< Run tests for each listed file
 };
 
 #endif