diff --git a/common/src/main/java/io/opentelemetry/common/impl/ConfigUtil.java b/common/src/main/java/io/opentelemetry/common/impl/ConfigUtil.java
index a129fd331bd..cd8ee760793 100644
--- a/common/src/main/java/io/opentelemetry/common/impl/ConfigUtil.java
+++ b/common/src/main/java/io/opentelemetry/common/impl/ConfigUtil.java
@@ -39,9 +39,13 @@ public static Properties safeSystemProperties() {
    * Return the system property or environment variable for the {@code key}.
    *
    * <p>Normalize the {@code key} using {@link #normalizePropertyKey(String)}. Match to system
-   * property keys also normalized with {@link #normalizePropertyKey(String)}. Match to environment
-   * variable keys normalized with {@link #normalizeEnvironmentVariableKey(String)}. System
-   * properties take priority over environment variables.
+   * property keys also normalized with {@link #normalizePropertyKey(String)}. Further normalize the
+   * {@code key} using {@link #normalizeEnvironmentVariableKey(String)} and match to environment
+   * variable keys normalized the same way. System properties take priority over environment
+   * variables.
+   *
+   * <p>For example, {@code otel.experimental.sdk.jvm_stacktrace} matches the environment variable
+   * {@code OTEL_EXPERIMENTAL_SDK_JVM_STACKTRACE}.
    *
    * @param key the property key
    * @param defaultValue the fallback value if neither system property nor environment variable is
@@ -61,8 +65,10 @@ public static String getString(String key, String defaultValue) {
     if (systemProperty != null) {
       return systemProperty;
     }
+    String environmentVariableKey = normalizeEnvironmentVariableKey(normalizedKey);
     return System.getenv().entrySet().stream()
-        .filter(entry -> normalizedKey.equals(normalizeEnvironmentVariableKey(entry.getKey())))
+        .filter(
+            entry -> environmentVariableKey.equals(normalizeEnvironmentVariableKey(entry.getKey())))
         .map(Map.Entry::getValue)
         .findFirst()
         .orElse(defaultValue);
diff --git a/common/src/test/java/io/opentelemetry/common/impl/ConfigUtilTest.java b/common/src/test/java/io/opentelemetry/common/impl/ConfigUtilTest.java
index 996376383af..de13d2bf69a 100644
--- a/common/src/test/java/io/opentelemetry/common/impl/ConfigUtilTest.java
+++ b/common/src/test/java/io/opentelemetry/common/impl/ConfigUtilTest.java
@@ -40,6 +40,7 @@ void getString_SystemPropertyNormalized() {
   @Test
   void getString_EnvironmentVariable() {
     assertThat(ConfigUtil.getString("config.key", "default")).isEqualTo("environment");
+    assertThat(ConfigUtil.getString("config_key", "default")).isEqualTo("environment");
     assertThat(ConfigUtil.getString("other.config.key", "default")).isEqualTo("default");
   }