diff --git a/README.md b/README.md
index 8c6f8e9d..f0451261 100644
--- a/README.md
+++ b/README.md
@@ -629,7 +629,7 @@ This increasing the chances and the probability a lot that the automatic install
 ##### Usage
 A New setting is introduced - `TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS` (as both env variable/key in `options` object)
 1. `TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS`="false" - install requirements.txt while respecting declared versions for all packages.
-2. `TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS`="true" - install all packages from requirements.txt, not respecting the declared version, but trying to install a version tailored for the used python version, when using this setting,you must set setting `MATCH_MANIFEST_VERSIONS`="false"
+2. `TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS`="true" - install all packages from requirements.txt, not respecting the declared version, but trying to install a version tailored for the used python version. When using this setting, you must set `TRUSTIFY_DA_PYTHON_VIRTUAL_ENV`="true" and `MATCH_MANIFEST_VERSIONS`="false"
 
 ##### Using `pipdeptree`
 By Default, The API algorithm will use native commands of PIP installer as data source to build the dependency tree.
diff --git a/src/main/java/io/github/guacsec/trustifyda/utils/PythonControllerBase.java b/src/main/java/io/github/guacsec/trustifyda/utils/PythonControllerBase.java
index c7441cb9..7ee7b385 100644
--- a/src/main/java/io/github/guacsec/trustifyda/utils/PythonControllerBase.java
+++ b/src/main/java/io/github/guacsec/trustifyda/utils/PythonControllerBase.java
@@ -75,12 +75,20 @@ void installPackages(String pathToRequirements) {
 
   public final List<Map<String, Object>> getDependencies(
       String pathToRequirements, boolean includeTransitive) {
+    boolean installBestEfforts =
+        Environment.getBoolean(PROP_TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS, false);
+    if (installBestEfforts && !automaticallyInstallPackageOnEnvironment()) {
+      throw new IllegalStateException(
+          "Conflicting settings, "
+              + PROP_TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS
+              + "=true requires "
+              + PROP_TRUSTIFY_DA_PYTHON_VIRTUAL_ENV
+              + "=true");
+    }
     if (isVirtualEnv() || isRealEnv()) {
       prepareEnvironment(pathToPythonBin);
     }
     if (automaticallyInstallPackageOnEnvironment()) {
-      boolean installBestEfforts =
-          Environment.getBoolean(PROP_TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS, false);
       /*
        make best efforts to install the requirements.txt on the virtual environment created from
        the python3 passed in. that means that it will install the packages without referring to
@@ -90,7 +98,7 @@ public final List<Map<String, Object>> getDependencies(
       if (installBestEfforts) {
         boolean matchManifestVersions = Environment.getBoolean(PROP_MATCH_MANIFEST_VERSIONS, true);
         if (matchManifestVersions) {
-          throw new RuntimeException(
+          throw new IllegalStateException(
               "Conflicting settings, "
                   + PythonControllerBase.PROP_TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS
                   + "=true can only work with "
diff --git a/src/test/java/io/github/guacsec/trustifyda/utils/PythonControllerRealEnvTest.java b/src/test/java/io/github/guacsec/trustifyda/utils/PythonControllerRealEnvTest.java
index 4aa98d2c..43fee7fd 100644
--- a/src/test/java/io/github/guacsec/trustifyda/utils/PythonControllerRealEnvTest.java
+++ b/src/test/java/io/github/guacsec/trustifyda/utils/PythonControllerRealEnvTest.java
@@ -17,6 +17,8 @@
 package io.github.guacsec.trustifyda.utils;
 
 import static io.github.guacsec.trustifyda.Provider.PROP_MATCH_MANIFEST_VERSIONS;
+import static io.github.guacsec.trustifyda.utils.PythonControllerBase.PROP_TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS;
+import static io.github.guacsec.trustifyda.utils.PythonControllerBase.PROP_TRUSTIFY_DA_PYTHON_VIRTUAL_ENV;
 import static io.github.guacsec.trustifyda.utils.PythonControllerBaseTest.matchCommandPipFreeze;
 import static io.github.guacsec.trustifyda.utils.PythonControllerBaseTest.matchCommandPipShow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -334,6 +336,21 @@ void get_Dependency_Name_with_extras_and_special_operators() {
         PythonControllerRealEnv.getDependencyName("package[extra]~=1.0 ; python_version >= \"3\""));
   }
 
+  /** Verifies that BEST_EFFORTS=true without VIRTUAL_ENV=true throws a descriptive error. */
+  @Test
+  @RestoreSystemProperties
+  @SetSystemProperty(key = PROP_TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS, value = "true")
+  @SetSystemProperty(key = PROP_TRUSTIFY_DA_PYTHON_VIRTUAL_ENV, value = "false")
+  void best_Efforts_Without_Virtual_Env_Should_Throw_Runtime_Exception() {
+    String requirementsTxt = getFileFromString("requirements.txt", "flask==9.9.9\n");
+    IllegalStateException exception =
+        assertThrows(
+            IllegalStateException.class,
+            () -> pythonControllerRealEnv.getDependencies(requirementsTxt, true));
+    assertTrue(exception.getMessage().contains(PROP_TRUSTIFY_DA_PYTHON_INSTALL_BEST_EFFORTS));
+    assertTrue(exception.getMessage().contains(PROP_TRUSTIFY_DA_PYTHON_VIRTUAL_ENV));
+  }
+
   @Test
   void automaticallyInstallPackageOnEnvironment() {
     assertFalse(pythonControllerRealEnv.automaticallyInstallPackageOnEnvironment());